Nualgi Ponds – 1L

Rated 4.53 out of 5 based on 217 customer ratings
(242 customer reviews)

$230.00 $195.00

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*Nualgi has a 3 year shelf-life!

An innovative approach to improving pond balance, Nualgi Ponds is built on a nano silica base with our patented formula of 12 essential elements that safely help restore the natural balance, improve water quality and control nuisance algae.

Engineered specifically to benefit the health of your aquatic plants and fish, Nualgi Ponds is easy to use, efficient, and yields rapid results.

SKU: np1L Category:
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Bottle Size Gallons of Water Treated Cost to treat 5,000 Gallons
60 ml 60,000 $2.08
125 ml 125,000 $1.60
250 ml 250,000 $1.40
500 ml 500,000 $1.15
1 L 1,000,000 $0.97

When you supplement your regular maintenance with Nualgi Ponds, you will be able to:

  • WATCH YOUR POND FLOURISH – Nualgi Ponds will significantly improve water quality as well as the health of fish and plants. For many eutrophic ponds, results may be visible by afternoon on the first dose– starting with the bubbling up of oxygen, elimination of odor, and Blue Green Algae crashing and floating to the surface.
  • SEE MORE – By reducing nuisance algae growth, Nualgi Ponds improves water clarity and visibility to reveal more of the pond’s environment and its inhabitants.
  • FEED LESS – By restoring missing nutrients, Nualgi Ponds brings balance to the natural marine food chain from the bottom up by promoting the growth of diatoms and zooplakton – free food for your fish and shrimp!
  • SHOW IT OFF – Enjoy peace of mind knowing that your pond is healthy, clear, and odor-free.  Friends and guests will be impressed, and we won’t tell them how easy it was to restore the natural beauty of your pond.
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242 reviews for Nualgi Ponds – 1L

  1. Jesus L. Opiana

    For pond safety i recommend this product you can see the result no worries losing fish.

  2. Took a risk

    Worked wonders! Have a 500 gallon pond with everything covered in a dark algae slime. Used the tiny amount as directed and all the slime just disappeared totally within three weeks and the koi and goldfish were unaffected and happy! Definitely use as directed. A very little goes a long way.

  3. Nikki

    We used this in conjunction with beneficial bacteria and our formerly pea soup pond is now clear after about 2.5 weeks of use.

  4. Mdink

    used one dose and see a difference already

  5. Karen Faulkner

    I tried using this as directed and it did nothing for the 200 gallon tank I had. So I tried doubling the dosage and still had no affect.

  6. Bill D. McArthur

    initially worked to help with string algae. But over the year, it didn’t work as advertised in controlling algae. finally had to drain and clean the pond. After we refilled and added this product, the algae came back

  7. Delores Underwood

    Love this product it may take a few weeks to see results when you first start but after that you will have crystal clear water and beautiful color added to your fish.

  8. Cortney Johnson

    works pretty good, water is super clear

  9. Scott Claason

    great product and great delivery

  10. Donald R. Shickle

    Clears up the pond pretty quickly. Should last long time.

  11. EBS

    Hello,Nualgi Ponds is a fantastic product! We have a 4500 gallon koi pond and algae began forming in late fall 2017. We applied the product and within two weeks and the algae was completely gone. The water is now crystal clear. Amazing! Will buy again.Thank you!EBS

  12. Ray Las Vegas

    Best product for algae control. The brown after effect is easily removed with a hose. I’ve tried everything else; this is great. Fish don’t seem to be affected by it.

  13. Nancy

    I would recommend this product. It cleared up my pond nicely.

  14. Gardot

    I noticed one thing that most reviewers don’t make clear is what type of algae they were trying to control, whether string algae or the single-cell variety that makes your water look like pea soup. From my experience this product worked very well to eliminate string algae but was absolutely worthless for controlling single-cell (green water) algae. So if you’re trying to control string algae, this product is likely to work very well. However, if you’re trying to control the single-cell (green water) variety, don’t waste your money on this product.

  15. Steven Yokum

    It took a month to see results. Which was stated as a possibility. During that time I did a lot of manual removal of the string algae. I probably scooped 5 pounds out of my pond. I’m not sure this would have been effective without doing that. At this point even the surface of my rocks are starting to clean up. So I’d say it works. I’m wondering if a little string algae may be good for the fish going into winter so today was my last treatment for 2017.I stopped using over the winter and the string algae exploded again. I started manually removing and using this again on my 1000 gallon pond this spring. Took another month, but once again it cleared the string algae out. I’d say manual removal is a must on the big strings

  16. John

    This stuff actually works. Not sure how, but I ,put in 2 mils for a week until algae was under control and now I use 1 mil per week for maintenance. The water is a lot clearer.

  17. Crystal Maddox

    This stuff really does remove algae from my pond!

  18. Katie And Gary

    Love this product … I’ve been using it for 3 years now and just wish they offered a larger size and brought their price down a bit. We have a 14,000 gallon Koi pond and a much larger natural pond in back that we cannot afford to properly treat. Sell me a gallon size and give me a break on the price please. I’m done with paying for products that do nothing and just take money out of my pocket.This stuff works.

  19. Trevorm

    This product worked as advertised. Excellent for my pond.

  20. Francs D. Irwin, R.N.

    Wow, we had emptied our pond and cleaned out the slug for years of accumulation. It was hot when we refilled it and within a couple of days we had really sick water, smelled, brackish, ugly. I put 1.5 cc’s in it daily for a few days and the water cleared, the smell was gone. Its now stable with putting 1.5 cc in once a week. Ready for fish now. Had lost our fish last winter. Some had been in this pond for 13 years. Nearly everyone in our area lost their fish last winter. The best product I’ve ever used for controlling algae and muck. The water lilies are thriving.

  21. Patricia

    Wow! This stuff really works??. I had been useing a UV light. That worked sorta, but made a lot of sludge on the bottom of my 6000 gallon pond ( a real pain to clean every 2 weeks). I started useing this product after I had cleaned the pond and it has been over 2 months and only a small amount of sludge. I could probably use a bio lift and that would clean uo the small amount that has accumulated. Make sure you turn off the UV light if you have one. This works!!!!

  22. Anthony Boccio

    This product is fantastic. If used properly, it works great. I used many other products before and NOTHING worked, this worked in about two weeks. My water is completely clear and pond is doing great. Great, great product.

  23. Cindy Patterson

    Best stuff ever.

  24. Morton Lin

    I have a water fountain with goldfish in it. I tried several products, and this one seem to work the best to control algae.

  25. Rated 5 out of 5

    Rosemarie Strum

    i didn’t think it would work as well as it does….my koi seem very happy and i can finally see them….

  26. Rated 5 out of 5

    Brian Black

    a new pond, several fish, new plants( plant fertilizer), this was a recipe for algae. I had always used barley straw along with a filter to keep my old smaller pond tolerable. I wanted better. Nualgi has kept my pond clear! my fish are happy and growing, so are the lillys and floating plants. Thank you

  27. Rated 5 out of 5


    Cleared up my waterfall stream within 3 weeks!

  28. Rated 4 out of 5

    Judy Pupek

    My pond has never looked better!

  29. Rated 1 out of 5


    This really works to keep my pond cleaner.

  30. Rated 3 out of 5

    Steven S.

    My 1500 gallon pond has been pea green since the second week I opened it in April. I was giving this product four weeks and then I was going to use an algaecide I had previously bought, but was afraid to use. Today is four week mark and earlier this week I awoke to a clear pond one morning. I am very pleased with this product. I had to clean my pressure filter today since the dead algae had clogged the filters and my water falls flow was greatly reduced. I have been noticing a smell and will see if this stuff takes that away – says it does. Now I have to worry about predators taking my 3 fish…lol.

  31. Rated 5 out of 5

    Blue Ridge Andy

    We have only used this product for three weeks but up to this point the results are promising. As instructed, before starting its use I thoroughly cleaned the pond which had a significant infestation of string algae plus a considerable amount of the slimy “clump” algae. While the string algae are completely gone some of the clumps have started to reappear in far smaller quantities. There are, of course, several variables. Among them Nualgi and the pond cleaning were algae reducing. On the other hand the fact that during the cleaning I had to get rid of some of the water plants (less surface coverage= more opportunity for algae growth) and the above normal temperatures in the last couple of weeks tended to be algae increasing. While it is impossible to isolate the influence of each of these factors, the combined total impact so far is encouraging.

  32. Rated 5 out of 5

    Amazon Customer

    I have had a 16000 koi pond for 15 yrs. I have never been able to keep it clear, even with UV lights…after trying this product my pond is now crystal clear…no UV lights and no other chemicals. I live in Tn and it gets really hot and humid but it seems with using this the hotter it gets the better it works….I am a forever customer for sure….

  33. Rated 5 out of 5

    Blue Ridge Andy

    We have only used this product for three weeks but up to this point the results are promising. As instructed, before starting its use I thoroughly cleaned the pond which had a significant infestation of string algae plus a considerable amount of the slimy “clump” algae. While the string algae are completely gone some of the clumps have started to reappear in far smaller quantities. There are, of course, several variables. Among them Nualgi and the pond cleaning were algae reducing. On the other hand the fact that during the cleaning I had to get rid of some of the water plants (less surface coverage= more opportunity for algae growth) and the above normal temperatures in the last couple of weeks tended to be algae increasing. While it is impossible to isolate the influence of each of these factors, the combined total impact so far is encouraging.

  34. Rated 5 out of 5

    Amazon Customer

    I have had a 16000 koi pond for 15 yrs. I have never been able to keep it clear, even with UV lights…after trying this product my pond is now crystal clear…no UV lights and no other chemicals. I live in Tn and it gets really hot and humid but it seems with using this the hotter it gets the better it works….I am a forever customer for sure….

  35. Rated 5 out of 5

    Amazon Customer

    This is the best! Tried other products and wasted a lot of money, they didn’t work.
    This worked in my 8000 gallon pond after 2 applications. Very impressive and didn’t kill my fish or plants.

  36. Rated 5 out of 5

    Mark A Bulle

    Product works as advertised only reason I gave it a 4 start verses 5 is I thin its a bit pricey. Here is a bit of my history. Late last year I started building a fairly large koi pond estimate about 24,000 gallon when completed. I installed the liner last fall and filled to the level I could until I completed the stone edging. Any how I could not wait tot ad a couple of koi added one last fall and one early summer. Once we hit May time fram e and the sun started to get more intense the water started turning green, it got to the point i could see waves of algae and only see the 2 fish when they popped up to get a bite of food. It took away the enjoyment of watching the fish when you could only seen them during feeding time for a few minutes. Well I still have not completed the full filtration system won’t till next year at my current pace so a UV is not on the horizon yet, may not be now. So I started looking for an alternative way to potentially control the green water. I am not a big fan of chemicals, basically because I use to be a salt tank guy and the few times I used chemicals in a salt tank it was not met whit positive results, some fish loss, but the fish may have already been on the way out before I ever treated who knows that is history but none the less its made me skittish. So after finding this product and researching all I could it appeared to be safe to try. on 7/8/17 I put my first done in follow directions to a tee even putting it in first thing in the morning. After the first week I did not really see any improvement, but I saw video that a guy did where he went through a 4 week cycle an did not really see a change int he first week either so I was not too concerned. I added my second dose according to direction on 7/15/17 and when I woke up the next day the water had turned a golden brown color in 24 hours so it appeared to me it had killed the algae. Now I estimate my pond right now based on fill level to be around 18,000 gallon and all I have running for mechanical filtration is a 5 gallon bucket hooked to trash pump, bucket filled with quit batting form Walmart. I change the batting about every 3 to 4 days as it plugs with pond waste by product. Also have 2 4 inch bottom drain diffusers hooked up so I have to water columns help create water movement and airiate the water. By 7/16/17 you could see the water starting to clear up and the fish a little deeper. Today at lunch I went home 7/18/17 and to my amazement I could now just begin to start to see the bottom of the pond its about 5.5 feet deep. So less than 2 weeks of use I have had a huge improvement and I expect as my 5 gallon bucket filter continues to run it will keep clearing out the dead algae and it will continue to improve further. I probably should have waited until I completed the full 4 week trial but I was so impressed with the way this product worked I could not wait to post my partial results. I can say also its changed the interaction of the fish. Prior to use the fish were much more skittish, they would come up for a grab of food and dart back down, now they lounge around more at the surface and don’t seem to be bothered with people activity. I think the lack of visibility in the water made them nervous as well because they could not see potential threat until the surface for food, not they see me and associate me with food and have started to react to my presence in a positive way, those fish smarter than I gave them credit. Anyway good luck to anyone looking to rid green water as this product gets my full endorsement. I should have taken before and after photos too late but I could share after photos.

  37. Rated 2 out of 5

    Bob Pletka

    This is the only product that has ever worked! In three weeks the water in my 3000 gallon pond was 50% clearer. Now four weeks in I can see the bottom of the pond and all my fish! Tried API Pond ALGAEFIX and I swear it made things worse… Nualgi is the real deal!

  38. Rated 5 out of 5


    This stuff is amazing!! My water is crystal clear! I would highly recommend! It is safe for the fish too

  39. Rated 5 out of 5

    Amazon Customer

    Good product works great

  40. Rated 5 out of 5


    I gave it a try, and wow…No uv filter for a year and a half and clear water. I have a 4k gallon koi pond with lots a koi. Works great.

  41. Rated 5 out of 5

    Barbara S. Delozier

    good product, but will need a lot more than a teeny bottle for a big pond

  42. Rated 5 out of 5


    I was completely shocked at how well this product works! I have a small pond of only 800 gallons with 5 goldfish and a few plants. It is new as of last summer, but this spring when the weather warmed up and the sun hit the pond, I had a string algae growth so thick I couldn’t see the fish unless they were at the top! I did some research and decided to give this product a try. I added the few drops required and cleaned my filter often. It didn’t appear to change until week 3 when all of a sudden I noticed I could see about 12″ deep and the next day it was completely clear! I stopped using the Nualgi, thinking the algae would not regrow, but after 3 weeks it was back. I immediately added the few drops again weekly and at the end of the second week now I have crystal clear water again with just the fine green algae on the walls. This product is amazing.

  43. Rated 4 out of 5

    L. Dillon

    We’ve just added the fifth application. The pond is so clear. The only other time the pond was this clear was when we drained it and added new water. We could see improvements week by week after the second application. The pond would get clean and wouldn’t get dirty quite so quickly. The applicator that comes with it is perfect – I can gauge the right amount to put in although we have only about 750 gallons of water in the pond.

  44. Rated 4 out of 5

    Amazon Customer

    Been four weeks now and water is clearing up. Product does what it says. Would recommend for any algae problem.

  45. Amazon Customer

    did’nt work untill the water warmed up ,then worked good

  46. Rated 4 out of 5


    Works great for lowering pH while killing algae

  47. Rated 5 out of 5


    In less than 2 days, my 1000 gallon pond went from so cloudy that I could barely see my koi to crystal clear.

  48. Rated 5 out of 5

    John D Enloe Jr

    Love this product! My pond has never been so clear.

  49. Rated 5 out of 5


    Really worked for my pond

  50. Rated 5 out of 5


    I have pond care and when I told them what I had gotten which was Nualgi, they were pleased and said they were good.

  51. Rated 5 out of 5

    Amazon Customer


  52. Rated 5 out of 5


    Perfect solution for algae control, .5 ml once a week is all I need to maintain my 800 gallon low pond. Best solution for algae control I have used.

  53. Rated 5 out of 5


    Years of fighting string algae FINALLY over. This stuff really works. We have a 600 gallon circulating waterfall and pond. Just a few drops once a week.

  54. Rated 5 out of 5


    ok job

  55. Rated 5 out of 5

    Joylin G.

    This is the best product you can add to your pond for healthy fish, plants and a better ecosistem. Im a M biologist, I has been working with ponds for over 20 years, I purchased my first bottle of Nualgi for just check if it really works, and it does. On market theres no miracle product, ylu just need to add the best products for your po d to flourish and rhis is one of the best product I have been dealing with, We use it on several maintnances on ponds, at each depending on the pond acts different ways but one shure thing, the fish are healthier, plants are better and the water quality is now the best shape ever. So buy it, with confidence.

  56. Rated 5 out of 5


    Tried other algae treatments with only limited success. My 500 gal pond had a chronic algae problem..looked like asparagus fern… five weeks of treatment, the algae is gone and the water is perfectly clear. Fish and frogs are OK, too.

  57. Rated 5 out of 5


    It worked great for in my pond through the summer and fall of 2016. First year to put it in through the Michigan winter and when the ice cleared (several times this year), no string algae even to date. Just the carpet algae that the fish need in the early spring when it’s still to cold to feed them. Fabulous stuff.

  58. Rated 5 out of 5

    randy a.

    Best product available that I have found for my coy pond.

  59. Rated 5 out of 5

    ron musgrave

    Works great.

  60. Rated 5 out of 5

    Purple Zinger

    I had my pond replaced this last summer with a new one. The new pond cycle seemed to be never ending with the pea green algae. First I used a product called Bio-pond which I bought on Amazon. It killed the different algae types growing in the pond, but didn’t clear up the pea green algae in the water. Perhaps I didn’t give it long enough to completely clear it all out. Still, it helped by getting rid of string algae that was just starting to grow, but I think it also killed the good algae that was growing. So I then switched to Nualgi, this is a cheaper product by comparison. It took a about a month and then the pond started clearing up. Now its crystal clear and I can barely see a slight green film on the rocks and falls. This is the beneficial algae that this product is supposed to help develop.
    Note: As part of my regiment I do a few partial water changes through the year. This will also help to clear out algae spores and help the product to work quicker.
    I also dose with beneficial bacteria and check Ammonia, Nitrate, PH, and other levels weekly. Nualgi will be part of my regular regiment from now on.
    Also, if you are feeding your fish with fish food, you will probably fight algae no matter what you use. I have to wonder if the folks saying this doesn’t work for them are dumping lots of fish food in the pond. I will have a better idea of that relationship next spring when I start feeding small amounts of fish food to my fish again.

  61. Rated 5 out of 5


    One of the best ways to control algae and keep your pond clear, I mean clear. I have never seen anything like this. My koi fish seemed more active and agile after administering product. Algae goes in about a day or two, All done, and hello clear water. If you have pond, you should get this.

  62. Rated 5 out of 5

    Ragtime Bob Krone

    Best product I’ve ever used (once per week) to eliminate String Moss!

  63. Rated 5 out of 5


    Works very well. exceeds my expectations.Does not control the long hariry algea but it says that on the bottle.

  64. Rated 5 out of 5

    Edward Campbell

    my pond I super clear thanks to Nualgi

  65. Rated 5 out of 5


    So far it is working great

  66. Rated 5 out of 5


    Cleared our pond

  67. Rated 4 out of 5

    S. Wong

    Seriously. this stuff works!!!
    My pond had suddenly gunked up with massive amounts of string algae. No matter how much I tried to scoop them out, they came back!!!
    After pouring a few ml of this, all the string algae are gone and the water in my pond has never looked so clear!!

  68. Rated 5 out of 5

    Amazon Customer

    Works great but be patient

  69. Rated 5 out of 5

    Linda S

    Our backyard pond is looking so much better already!

  70. Rated 5 out of 5


    I have fought Koi pond algae for years and have tried it all and use UV lights , beneficial bacteria, algae Fix. So I was skeptical but within two weeks of using this product my water was very very clear. . So Far so good after 1 month.

  71. Rated 5 out of 5


    I could not see any difference in the pond water clarity. I have a ultraviolet light in operation also.

  72. Rated 5 out of 5

    James H

    My pond so far is clear of algea

  73. Rated 5 out of 5


    I was extremely skeptical about this product, the reviews were either glowing or unimpressed. I thought I’d give it a try. A new rental house had an existing koi pond with no fish, it was really murky, the visibility was just a few inches. We bought some koi & bought some plants, added some cloth filters. I added Nualgi to the water at the same time. Within a week, I could see the bottom of the pond, it’s about 4 feet deep. I think the pond cleared up with the combination of things I did, so I can’t confirm that Nualgi was the reason, but the pond is clear, the long algae and green algae is gone, I’m happy with the purchase.

  74. Rated 5 out of 5

    Lynn P

    It works fantastic!! Highly recommend it.

  75. Rated 5 out of 5

    Craig J

    This was almost a one star failure review but I’m pleased to say my pond is now crystal clear. I used the product for almost 6 weeks with no discernible affect, in fact the water got greener and greener until I could only see blurry shapes of color where my koi were. I finally took lots of pictures and submitted to Nualgi’s troubleshooting page. Christian and I conversed back and forth and never really figured out why my pond was taking so long to clear, but I began dosing every other day for a week and then once every 4 days. Finally, almost overnight, the pond was clear to the bottom (4 feet). I am still playing around with the dosing but it looks like I will have to dose every 4 to 6 days, at least during these hot sunny summer days. I can see a difference in my water when a new dose is needed but I watch my pond closely everyday anyway. My advise is to try this product and be patient. If you don’t get the miraculous results some experience after a couple of weeks, try dosing more frequently. Of course, make sure all other water parameters are correct. The bottom line, I’ve reordered a new bottle.

  76. Rated 5 out of 5


    didn’t appear to have much effect on the algae in my pond ..

  77. Rated 5 out of 5

    Elizabeth D

    keeps the pond clean!! great!!

  78. Rated 5 out of 5

    John Shuel

    This stuff is AMAZING. We started it in the early spring and it took about 2 months for ALL our string algae to finally die off. Its 108 F for the last 3 days and NOTHING has started. I can now enjoy my pond and koi. THANKS

  79. Rated 4 out of 5

    Bob Powell

    Want to make sure I keep using every week I’ve noticed a big difference definitely going to keep using this product

  80. Rated 5 out of 5

    Phillip D

    Great crystal clear water but still got algae on rocks and plants.

  81. Rated 5 out of 5

    Tracey J

    Love this product. It has totally changed my pond. The algae is kept to a minimum & the clarity in the pond is wonderful. I for sure recommend it. I had tried many products for my string algae & nothing has helped as much.

  82. Rated 5 out of 5

    Rich S

    My pond had a lot of green algae that was turning dark brown. I used several expensive pond products that did not help. I added .5 ml of Nualgi Ponds as directed. A week later I added another dose and by the end of the second week there was no visible algae. This is a great product.

  83. Rated 5 out of 5

    Tracy P

    Cleared my water after 3 treatments

  84. Rated 5 out of 5


    This stuff goes way beyond my wildest dreams!! My 3000 gallon pond is maintaining itself without any UV lights to help out and said lights have been turned off for 3 weeks now. Try it, you’ll like it!!

  85. Rated 5 out of 5


    This product did nothing for the algae in my pond. I started with the stated dose. When nothing happened I doubled the dose. At the end I dumped the whole bottle in. Guess what? My pond is the same as it was before. Not having to use chemicals was too much to hope for I guess.

  86. Rated 5 out of 5

    Doris A

    I was skeptical that this stuff would work, but it did. My pond was such a mess, I drained it, replaced all of the filtration media, and started over. Of course, the green algae bloom was back in a day. I started using this stuff at the start, back flushed the filter every few days to get rid of the black stuff-dead algae, I suppose. And after the third weekly dose, the pond water is totally clear. I have to use a syringe to measure it out, the dose for a 500 gallon pond is so small! Pretty amazing in my book.

  87. Rated 5 out of 5

    Tara W

    If you get this product and the color of the algae is brown, you are good. Beware, if the color of the algae is green, it will cause severe algae bloom. They also state that it has a 3 year shelf life, this is not true…I will not buy this again, it is to risky.

  88. Rated 5 out of 5

    gene l

    I am not sure if ti works or not. I have been rebuilding a pond I inherited when I bought this house. I removed a tree dropping debris over the pond but there is still another tree over the pond. I have been using Nualgi for three weeks but also have added more plants, added more shade over the pond, and have added nitrate destroyer. I have not yet learned where the filter is yet, suddenly it seems over the last day the water has really cleared.

  89. Rated 5 out of 5

    Delwin T

    So far it has worked just great. we will have to see when it gets hotter.

  90. Rated 4 out of 5

    Amazon Customer

    I was skeptical about the claims, but as I needed to try something, I gave it a try. Before the end of the first week, I could see a difference in the water. I gave it a second dose after a week as instructed, and the water is almost clear. I would highly recommend this product- it has made all the difference, and we don’t run the pump itself for more than 4 hours a day.

  91. Rated 5 out of 5


    I have 3 ponds total 15000 gallons. Usually able to control green water with copper but lots of rain this year son not working totally, tried nualgi and I saw ZERO effect. I will not buy again!!

  92. Rated 5 out of 5

    Amazon Customer

    Nualgi Ponds worked beautifully after three doses. I could see the bottom of the pond and it is 4 feet deep. I love it because now I can see my koi all the time instead of just when they come up to feed. I will keep using this throughout the summer and until cold weather.

  93. Rated 4 out of 5

    Amazon Customer

    It worked as described it would

  94. Rated 3 out of 5

    Radio Man

    I hate to leave negative reviews but if anything my 7500 gallon Koi pond is actually MUCH more green after three weeks using Nualgi, than not.
    Maybe because members in my family had cancer I ALMOST feel this product is like one of those too good to be true products. What I mean is, in illness people start grabbing at straws…many say, oh it’s just $20 or in illness that could be oh, it’s just $500 “lets try this.” Well maybe a dumb analogy but I feel many pond owner get so desperate to get rid of algae in a natural way, they like me may have the mind set, oh it’s just $20 give it a try. Those $20 can really add up for profit. I am in no way actually saying this stuff is some sort of placebo, but it sure didn’t work for me. Like many, I have followed the directions exactly, maybe even used more of this stuff than it says to. After three weeks I can barely see down 1 inch literally as my pond is so green. I will admit I have not balanced my water in the last three weeks but about a month ago had a test kit and my water was all ok other than it being rather green like a frog! The only NATURAL product I ever used in my pond that COMPLETELY TRULY cleared my water up so I could see the bottom again is a product called Acurel. In 2 doses my pond went from pea green to clean as almost tap water. I just hated it worked so well, I had to clean my 5 filter pads right after treatment as they got so gunked up so quickly. In any case this Nualgi didn’t work at ALL at ALL for me. I appreciate the manufacturer comments on most of these reviews and offers more help supposedly, but who wants to work THAT hard jut to have a clear pond. I dunno, I am very disappointed with this product and if it means anything this may be the first real negative review of almost any product I ever wrote. Hope it works for you, there are several positive reviews here. I wonder if my batch maybe came from another planet? :)…for me this was just a waste of $20.

  95. Rated 5 out of 5

    Barbara B

    Yes, it does work. The water in my fountain comes clear within a couple of days thanks to Nualgi Ponds. My goldfish are unaffected.

  96. Rated 5 out of 5


    It took a few weeks to start working but it has been a year now, algae free!

  97. Rated 5 out of 5

    Jack (verified owner)

    We have a very small backyard pond that we dug 3 years ago. I have a few freshwater fish in there that I caught in a local river and released into the pond to grow. I also have several water plants from that river growing as well as giant elephant ear plants all around the pond. The floods we experienced in South Carolina last fall caused this pond to overflow onto the surrounding area for quite a while. Apparently, fertilizer that we had put out ended up in the water and we experienced an algae bloom that was a thick pea-green muck. My fish were gasping for air at the surface and some died. I found this product on Amazon and have used it 2 times since receiving and the pond is almost completely clear. Probably, 1 more application will do it. It was a fairly expensive item but proved to be worth it.

  98. Rated 4 out of 5

    Jim W

    This stuff is the best treatment I have ever used. It didn’t work at first because I had other treatments in to clear up the water. I have a190 gal. pond and so I drained 80% of the water and started fresh, then waited a couple days and then I added Nualgi following directions and it’s been crystal clear for weeks.

  99. Rated 5 out of 5

    C. P.

    Only one con, you have to use more than directed to clear up Algae

  100. Rated 5 out of 5

    Diane J

    This works wonderfully. My water is clear and the algae is almost totally gone. I will continue using it and would recommend it to others.

  101. Rated 5 out of 5

    Dora L

    The product works well when dosed as directed. Pond is clear; fish are healthy. It is pricy but lasts a long time as you don’t use very much per dose.

  102. Rated 1 out of 5

    Mr L

    No big change. Seems to be working but hard to tell so quickly.

  103. Rated 1 out of 5


    It did not work at all even after using all of the bottle which was to last several weeks and our pond is small. Had great reviews but did not work for us.

  104. Rated 5 out of 5


    I’m struggling to like this product. My water is still not clear. I have no fish and no plants in my 1,000 pond.

  105. Rated 4 out of 5

    Amy (verified owner)

    We purchased this for our 8,000 gallon koi pond last year after giving up on everything else working. We started dosing after the pond was quite overwhelmed algae. Frankly, it did not make much of a difference, but we figured the algae was already so bad, we couldn’t fault the product. We determined to try Nualgi again after winter had killed the algae and while the pond was still clear. We did that in early spring, and for the first time in 9 years, we still have clear pond water and can see the fish though it’s already summer sun and heat here in the SE USA. This is a win. We’re glad we tried it the second time. We’ll be buying more. To those considering using Nualgi, I would recommend using it sooner rather than later. If your pond is already overwhelmed with algae, it may not work this year. Don’t give up. Use it early next year. It does work.

  106. Rated 5 out of 5


    May work for some but not me. Did not see any change in my pond at all.

  107. Rated 1 out of 5

    Fulton A

    The product worked very well and my pond cleared up in 3 Days!!!!

  108. Rated 3 out of 5


    So far seems to be helping to control string algae in our koi pond.

  109. Rated 2 out of 5


    had green stringy algae, and it cleared up within a week. Was very happy with this product. I have been using it weekly and no more algae!

  110. Rated 1 out of 5


    Third dose and my pond seems to have less algae than last year

  111. Rated 3 out of 5

    Bob W

    Do not doubt this product……

    After only 3 weeks I have noticed a definite clearing of the Algae in my 3,200 gallon back yard Koi pond. I AM impressed.

  112. Rated 4 out of 5

    M. R.

    I have had years of experience with garden ponds. This is my third. I am in Los Angeles, and the pond gets a lot of sun. My other ponds contained koi, but this one contains just 9 large fancy goldfish, several paradise fish, and three waterlilies. It is 1,400 gallons, has a oversize filter (suitable for 10,000 gallon pond) and a 36 watt uv clarifier. As with my other ponds, the water is generally crystal clear, but, as before, I have had a continued battle with string algae. I learned about Nualgi in a google search. The promised results sounded too good to be true, but I contacted the company, described my pond and asked whether the smallest, 60 ml bottle, would suffice as an experimental sample. They suggested that, yes, that should last me 40 weeks. They also suggested that I turn off my uv clarifier. When I received the bottle, barely larger than my thumb, I wondered whether I’d been duped out of $20. I also decided that I would not shut off my uv. My pond, at this point, was thick with string algae. I added the required few drops of Nualgi once a week. The algae turned brown and began dying off the first week (but I considered that this might just me a natural die-off, as there had been so much.) Over the first couple of weeks, there was still some new string algae, and I spent hours vacuming up the dead clumps. The product seemed to be working, but struggling, so I reluctantly turned off the uv clarfier……It has been about 3 months. The water is crystal clear and there is only a pleasant green patina of green covering the walls. Virtually no string algae remaining. I guess my uv clarifier is obsolete. I have never enjoyed my pond more. To say that Nualgi surpassed my expectations would be an understatement. Great, great product for the pond enthusiast.

  113. Rated 5 out of 5

    William C

    worked great

  114. Rated 5 out of 5

    A. C.

    This is all I use in my pond now. We are in SC and have a 2900 gal. pond. Nualgi once a week keeps it in great shape. In the spring, I double dose for a few weeks, and it takes care of all the algae that accumulates in our mild winters.

  115. Rated 3 out of 5


    I had excellent results in exactly 30 days. While I was tempted to increase the dosage, it didn’t speed up the results but now I can see all my fish in the 150 gallon pond that’s in direct sunlight for 10 hours a day. I don’t have to constantly clean algae out of the filter to keep the fountain working anymore. Nualgi is a great company with fast and helpful responses to questions. I have shared the success I had with Nualgi to my pond owning friends.

  116. Rated 2 out of 5


    After a couple weeks, Nualgi seems to be working as advertised and fish are happy

  117. Rated 1 out of 5


    In my second year of owning my 800 gallon pond, I was having a very hard time getting it to clear up. After a few unsuccessful tries with other products, I found that Nualgi works exactly as advertised! My pond is very clear now and my goldfish and shubunkin seem to be perfectly happy/healthy. Easy to use, small amounts go a long way. Great product!

  118. Rated 3 out of 5


    So far so good – Nualgi is keeping my pond water clear. Fish colors are improved. They are happy and healthy.

  119. Rated 5 out of 5


    My pond is clean from algae. Thanks to Nualgi.

  120. Rated 5 out of 5


    Great service, great product

  121. Rated 5 out of 5


    Fast delivery, great product. Will buy Nualgi again.

  122. Rated 5 out of 5


    Awesome product. Nualgi works great.

  123. Rated 4 out of 5


    Nualgi appears to be working great!

  124. Rated 5 out of 5


    Nualgi really works!

  125. Rated 4 out of 5


    Miracle juice, I believe it helps

  126. Rated 5 out of 5


    I’ve been dosing with Nualgi and Microbelift PL for two months now. My pond is clear as ever – even in July when it’s typically infested with algae. Great product!

  127. Rated 5 out of 5


    Nualgi seems to be very effective. It seems too good to be true but it does work on my 1400 gallon pond. The water is definitely more clear.

  128. Rated 5 out of 5


    Nualgi seems to be hard at work on the algae that I have been struggling to control. Nualgi is easy to use and was a great find.

  129. Rated 5 out of 5


    Nualgi works as described, completely satisfied. It’s slowly, but surely working. Almost three weeks in.

  130. Rated 5 out of 5


    I have had my pond for over 3 years and it has been green from the beginning. After using Nualgi for the first time, I noticed a difference after just a few days. It has now been 3 weeks and I can see the bottom of my pond! It’s still a little murky so I’m hoping for more improvement. I’m very satisfied with Nualgi.

  131. Rated 5 out of 5


    My 1500 gal pond in Arizona spends 340 days of the year in 80 degree and higher sunny temperatures. I have battled algae for years. So imagine my surprise when this 12 oz bottle of Nualgi arrived, I used the small dropper to add the 1.5 mls dose of Nualgi into my pond. That was 4 weeks ago and now my pond remains crystal clear with just this 1.5 mls dose a week being added. Love this product!

  132. Rated 5 out of 5


    I waited two weeks after dosing Nualgi. NO MORE ALGAE. Very happy so far with the product on my 5000 gallon pond. Whenever I contacted customer service, I got a reply as early as the same day.

  133. Rated 5 out of 5


    Love it! I haven’t seen the bottom of my pond in a long time. After using Nualgi for less than two weeks, my pond is clear…… I’m so glad I found it. Will reorder soon. – Nancy H.

  134. Rated 5 out of 5


    I am entirely satisfied with Nualgi. I will order it again in the future and recommend Nualgi to others – Denise Denton.

  135. Rated 5 out of 5

    Michele F.

    Small turtle pond…works well. Seems to be working slowly, but much better than the other things we have tried. Will continue for sure.

  136. Rated 5 out of 5

    Dr B

    Works as advertised. It has cleared up my Koi pond and kept it clean.

  137. Rated 1 out of 5


    This is a preliminary review, as I have on;y had the product for a week, but so far I could not be happier! For the first time I had quite a bit of string algae, and hoped this would help. I the very small recommended dosage in my 1000 gallon pond Sunday morning, and by the time I checked Tuesday morning it was completely gone! I will update if things change, but I have high hopes!

  138. Rated 1 out of 5


    I tried Nualgi Pond and will never use a another harsh chemical algaecide again. I love the product; it costs less and works better. I also added 3 plecostomus last year to my 16,000 gallon koi pond and let me tell you, they grow really fast in the pond. But Nualgi did a great job keeping it clean of all algae. I have bought 5 more plecos already for this spring so I can add to the pond as soon as the water warms up to help the other 3 I have.

  139. Rated 5 out of 5


    I have been using Nualgi for about 8 months now and it works great. Crystal clear water. Nothing I have used before gave me these results. You’ll notice a difference in about 3 weeks. It doesn’t take much either. I highly recommend.

  140. Rated 2 out of 5


    I have been using this product for about 2 months in my 12,000 gallon koi pond and my 1,100 gallon quarantine pond. I am very pleased with the results. The string algae is completely gone and I no longer have to run my UV lights 24/7. My bead filter has not needed constant backwashing and cleaning since I started using Nualgi.

  141. Rated 5 out of 5

    Omar M

    I’m a witness that Nualgi works. My pond is a far cry from the green mess that I had over a year ago. I worked with Nualgi and Christian to get my pond looking great.

  142. Rated 5 out of 5


    I highly recommend Nualgi. I moved into a home with a cement Koi pond and it was like pea soup. After following their advice and using their product, look at it now! So happy with this product!

  143. Rated 2 out of 5


    I used my last dose of Nualgi 9 days ago. My water is still clear. I have also turned my UV light off for the first week of October and never got any green water later. I intend to use Nualgi next year as well. This is the first year in 13 years that I didn’t use a UV lamp. It was so nice not having to put the UV light in the Spring and then removing it in the Fall. I decided to try Nualgi and not use my UV lamp at all. In my case, it paid off. Nualgi is much cheaper than a new bulb.

  144. Rated 5 out of 5


    Nualgi works good. Great product.

  145. Rated 5 out of 5

    cheryl k

    I do not see any difference in my pond??

  146. Rated 5 out of 5


    My bright green pond cleared up in two weeks. I can see the bottom of the the pond and the fish again. So far Nualgi seems to be working exceptionally well.

  147. Rated 2 out of 5


    Not what I expected. Has not performed as anticipated nor published.

  148. Rated 5 out of 5


    This product kept our pond clear without using a UV light! Remarkable!

  149. Rated 5 out of 5


    I was VERY skeptical about buying this product, The cost seemed high and the claims it made seemed too good to be true. I ordered my first bottle at the beginning of the long and hot Florida summer. Guess what? It was everything it claimed to be. My pond was crystal clear all summer. You use an extremely small amount of Nualgi each week. The bottle lasted about 4 months in my 4000 gallon pond. I also have a biological filter and a UV light. Nualgi says I don’t need a UV light so I decided to leave well enough alone since my pond water was so beautiful all summer. Happy ponding!

  150. Rated 3 out of 5


    This stuff is great! I’m looking forward to starting the pond next summer using Nualgi right from the beginning. It really goes along way too. My pond is ~1000 gallons & I just need 1 ml/wk. I could have gotten a smaller bottle. The attached pictures are from August. The water is so clear you can see fish & tadpoles clearly. The tadpoles are on a shallow shelf.

  151. Rated 2 out of 5


    I’d been battling to control the algae for 2 months. Within 1 week of using Nualgi, I began to see improvement. And by the end of 2 weeks, I could clearly see the bottom of the pond and my fish.- Mark V

  152. Rated 4 out of 5


    I’ve been trying this stuff for months, and it just doesn’t seem to work in my 50 gallon pond. It gets a lot of direct sunlight, so maybe that is the problem? I also thought I was using too little, so I started pouring in more than the dosage on the bottle. So far, no luck. It seems likely that I will use up the bottle and still have a pea green pond.

  153. Rated 5 out of 5


    Great product! My pond has really cleared up a great deal.

  154. Rated 5 out of 5

    kenneth g

    Does nothing…. Sorry

  155. Rated 1 out of 5

    J. Virgil C

    Product effectiveness not as advertised.

  156. Rated 5 out of 5

    Justa R

    Does not help with string algae

  157. Rated 5 out of 5

    Steve C.

    it works magic in my 1400 gallon pond! I am so happy with this product! It seems expensive but it takes so little each week that it really is a bargain.

  158. Rated 3 out of 5


    Using Nualgi in a showcase pond. Looks like it is working.

  159. Rated 5 out of 5

    John S.

    two weeks in, could read a newspaper if it was on the bottom of the pond. Cost seems high but dosage is very small. quite happy so far.

  160. Rated 5 out of 5

    Bruce P

    So far… it has not changed a thing. I’ve been using it about 3 weeks so the jury is still out. I have not had one of these wonder products that worked yet so my hopes are high that this one does.

  161. Rated 2 out of 5


    Won’t kill your fish. Nualgi works great.

  162. Rated 3 out of 5


    I saw great results the first week I used it, but now after 3 weeks of use my pond has become brown and I can’t see the fish anymore. My pond is 300 gallons. I don’t usually have a problem with clarity, but I tend to get some string algae. I’ve only been using .3ml when I dose the pond, since 1ml will treat 1000 gallons. I’ve done water changes to make the water clear, and I haven’t found anything that would cause the discoloration.

  163. Rated 3 out of 5

    Donna M

    We ordered the product because it said it would clear up the water in the pond. We followed the directions and after about 3 weeks now, there is some clearing but not what we expected. Water is NOT clear and we still have algi. We have used other products in the past that seemed to work much better.

  164. Rated 5 out of 5

    Pat K.

    Just wanted to say how great nualgi is working for me. Also the tech support helped me treat my sick fish and rid them of anchor worm was outstanding and so much appreciated. The water is crystal clear and my fish are looking really healthy. Thank you and I recommend Nualgi to anyone who has a pond.

  165. Rated 5 out of 5

    Paul R.

    On the 30th Day the water cleared to crystal! I could count my fish for the first time in a long time.

  166. Rated 5 out of 5

    Lynne S.

    Very happy with this product! Our pond is clear and the koi are thriving 🙂

  167. Rated 2 out of 5


    I’m only 3 weeks into dosing my 1,200 gallon koi pond with Nualgi and I’ve seen significant improvement in both water clarity and fish health. So far so good!

  168. Rated 5 out of 5


    This stuff really works. Check out their website and see how other environmentally “clean” states use it in their lakes. We use just a wee bit in our small pond and the water is clear and healthy.

  169. Rated 5 out of 5

    John P.

    I have been using it for 4 weeks now. It cleared up both ponds. I can see all the way to the bottom. Seems to work great.

  170. Rated 5 out of 5

    Susie S.

    Been in the water garden business over 15 years. This is what we now use in our ponds and in all the ponds we maintain. It is, without doubt, the BEST product on the market!! We call it our “magic elixir”.

  171. Rated 5 out of 5


    I am waiting, waiting, waiting for results. I just did the third dose, see no results so far.

  172. Rated 5 out of 5

    Sharon R.

    We put a pond in ,after 2 weeks was it was full of algae and water was not clear at all, my husband researched all over and this was one of the top rated products. We used it and it started clearing up within a week and have been faithful in using it and could not be any happier!!!

  173. Rated 5 out of 5


    I had been working on the algae in my pond for months when I discovered this product. At first I hesitated to spend this much on something I’d never heard of, but I’m so glad I did. It is amazing. I put it in and waited, within one week almost all the algae was gone and by the end of the second week it looked like a new pond!!! I recommended it to my daughter and wouldn’t hesitate to recommended it to everyone who is struggling with algae.

  174. Rated 5 out of 5

    Nancy S.

    I must admit that I was skeptical when I purchased Nualgi but was willing to give it a try. Since adding a biological waterfall filter two years ago, the water in my 1000 gallon pond has been green in spite of the use of beneficial bacteria, I started adding Nualgi at the beginning of June, and didn’t notice a change initially. However, starting week 7, the water started to clear and after dose 8 at the beginning of this week, I can now see to the bottom of the pond.

  175. Rated 1 out of 5

    Dionne C

    I received it accordingly but I have used it 2x but I have not seen a difference.

  176. Rated 5 out of 5

    Judith B.

    So far this looks like the best algae control investment I have made in 5 years. I have a well established pond that developed a string algae problem with rain and heat. I think Nualgi and my initial cleaning are the keys to getting this under control and leaving the rest of the summer to Nualgi.

  177. Rated 5 out of 5

    Tammy R.

    This product is amazing. Not only did it do what it was intended to do but it did not take nearly as long as the bottle stated. I highly recommend this product to all pond owners!!

  178. Rated 5 out of 5

    Kim P.

    I have to agree this stuff is amazing. Had a real fight with algae last year starting using this i our pond and the problem is SOLVED. The aquarium one is also amazing..

  179. Rated 5 out of 5

    Judi W.

    My pond has never been this clear! I am so happy to see my fish each and every day !!

  180. Rated 5 out of 5

    William E.

    I found Nualgi Pond on Facebook and read the many customer reviews with a bit of reservation, but other products I had tried wasn’t clearing the pond water of the algae, so I decided to give it a try. The instructions said that it may take up to 8 weeks application to clear the water; in my case it was right about then when I could see the bottom of my pond and all the fish. They have an online calculator to help you determine the proper dosage the product is easy to use with the provided measuring tool. I’m new to the pond and fish experience and learning with the help of people at Nualgi Pond and other sources. My failure to keep the pond aerated over the Winter probably caused the algae build up. With continued use, the water should remain clear.

  181. Rated 5 out of 5

    Erin M.

    Helped to clean the water of my pond. Didn’t realize at first that I needed to do a double does to really shock it. But I figured it out. Helps keep my koi pond really healthy. Now, did it take away the algae that was on the rocks? No, but as I studied more, that is supposed to be good algae? I had to hand harvest all the string algae and it hasn’t come back since then, and no more pea soup water, so I can see my koi, I can even see the black koi?! I have continued to use it weekly, and I will buy again to maintain my koi pond, but ultimately I will need to have it professionally clean out and then use Nualgi to keep it from getting too bad.

  182. Rated 5 out of 5

    Mike, Redding CA

    I have used Nualgi for approximately 5 weeks. I have also used other algaecides in my pond. I have a 5,000 gallon koi pond; gunite, with a bottom drain, skimmer, pre-filter basket and a large sophisticated micro bead filter system. I was also using a very large UV light until I found Nualgi.
    This spring when the pond started to warm and the fish started to wake up my pond turned green. It was so green in fact I could not see the fish unless they were eating. I tried a large number of bacteria fixes to no avail.
    I first saw Nualgi on a Facebook link. I called the owner and talked to him for a very long time. He gave me the most important word of advice there is. Be patient. And just when you think it is not working, be patient a little more. It takes about 4 weeks of dosing and your pond will finally clear. Some have seen shorter time periods, for a body of water like mine it is about 4 weeks. I added a little bit of Microbe Lift PBL and also did the most important thing. I turned off the UV light. Completely. The bacteria needs to generate and go to work. The light is directly counter to that theory.

    I quit flushing my bead filter as much, let the Nualgi go to work building colonies of algae eaters and let nature take its course. It really works. I rarely write reviews, but this is worth your time. For those that say it doesn’t work, it is because they do not wait long enough to see the results. Buy it, set your smartphone to Sunday morning, add a few eye dropper fulls and let the rest happen naturally. My plants are healthier, the water is clear and I can see every detail. The product is very concentrated; a little goes a very long way.

  183. Rated 5 out of 5

    Dot M.

    It took at least 8 weeks to clear up, but the pond is crystal clear, the prettiest its been in several years.
    The product seems to also be good at cleaning the scum off the rocks.
    Very impressed that using so little accomplished so much.

  184. Rated 5 out of 5

    Rhonda H.

    I’ve had great results with this product. Granted it has taken a little longer than others. We can now see to the bottom of our pond and are finally seeing all of the babies that have been hidden by green water! I am very pleased and will continue to use Nualgi.

  185. Rated 5 out of 5

    David A.

    My pond has never looked better since I started using your product. I used to have to pull out blanket weed daily since my pond is in full sun all day long. My fish and plants have never been happier. Now I can finally focus all my time on finishing all the landscaping around the outside of the pond. Beyond thanks for this product and your research in bringing it to market.

  186. Rated 5 out of 5

    Susan R.

    I LOVE Nualgi!!!!!! It has made a huge difference in the clarity of my pond water. Thanks for a super product.

  187. Rated 5 out of 5

    Russell P.

    I have been using it since 8/14 and have had all of my UV lights off since then. It saves me app. $100.00 a month in electricity costs

  188. Rated 5 out of 5

    Don G.

    I have a 2000gal rubber liner pond 3ft deep approx 19 years old which had some string algae and quite a bit of suspended material, Within two weeks there was noticable clearing and after 4 weeks it remains clear. Its not crystal clear like bottled water, but I can easily see details on the bottom, including fish–makes it more enjoyable to have them more visible.

  189. Rated 5 out of 5

    Dawn H.

    Did wonders for my pond!!! Love this stuff.

  190. Rated 5 out of 5

    Sue W.

    it worked awesome. Thank you so much. No more green water and no more smelly water!

  191. Rated 5 out of 5

    Steve C.

    How can those few drops make a pond so clear? All I know is that it works! It is amazing! I am so happy to have found this product. My pond has never been easier to manage and has never looked this good!

  192. Rated 5 out of 5

    Nancy H.

    I have put 2 doses in. CLEAR! Love it. I can see the bottom of my pond.

  193. Rated 5 out of 5

    Leann H.

    i have been using nualgi for about 6 weeks the stuff is amazing…my water is so clear it looks like i just filled it…also i dont know if its just me or what but i really believe my fish have grown faster than ever before…i will never be without it!

  194. Rated 5 out of 5


    Works well, however I live in Henderson NV and it is very hot! To keep the algae at tolerable level I have to dose twice a week and also use twice the amount called for. There is still algae, but at a tolerable level. I haven’t used algaecide once this summer which makes me happy and I’m sure all the creatures that drink from the pond are happy also.

  195. Rated 5 out of 5

    Thrifty shopper

    Product works well, keeps the pond looking clean and clear. I was expecting a larger bottle though

  196. Rated 5 out of 5

    Raymond J.

    I tried this product and it is truly amazing my water is so clear you could read a credit card on the bottom of my pond

  197. Rated 5 out of 5

    Thomas P.

    My pond is getting clearer by the day going on three weeks of treatment. Great product! ­

  198. Rated 5 out of 5

    William E.

    I can see bottom of pond clearly now and should be crystal clear in a couple of weeks; Nualgi Ponds does work as described. I recommended this to a friend with the same issues.

  199. Rated 5 out of 5

    Robert C.

    I have used three treatments of Nualgi Ponds, my pond went from pea green to near perfectly clear. I am very happy with your product.

  200. Rated 5 out of 5

    Barbara B.

    It did not meet the expectations we had hoped for.

  201. Rated 5 out of 5

    Debbi D

    I have used Nualgi for about 3 weeks. I have fairly clear ponds for the most part, but in an effort to make them even clearer I tried this product. I think it is really helping. I am cleaning my filter more right now, but that is slowing down as it stabilizes. I think Nualigi is going to be a good purchase.

  202. Rated 5 out of 5

    Janie O

    We have only treated our pond twice so far and see no difference yet. It’s done once a week and after almost three weeks it’s still real green and we are unable to see in the pond as before. I sure hope it doesn’t take much longer, but with the tiny amount we are using, I don’t see how it’s going to clear up at all. Any tips or advice is greatly appreciated. Thank you.

  203. Rated 5 out of 5

    Ari T.

    Before trying Nualgi, I was running 2 extra pumps and two UV lights to hold off the algae blooms in this Louisiana heat. I could tell that they were constantly struggling to keep up. After using Nualgi for about 3 weeks there was a noticeable improvement in my water clarity. Now, 12 weeks in, my pond looks crystal clear even in mid June. I’ve recommended this product to the members of my koi club, the members of our Facebook group and several other koi keepers in my community who’ve fought an uphill battle with green water. Many had tried algaecides in the past and suffered fish loss by doing so. This stuff is entirely safe for your fish and your plants as well as the delicate biological balance of your little ecosystem. I’m extremely pleased with Nualgi and I’ll continue to promote and use this product.

  204. Rated 5 out of 5

    Sherri M.

    OMG…I purchased both the inside fish tank and the outside koi pond; by the second treatment (7days) I could almost see through, after a couple of more days I can see the bottom. This stuff is wonderful!

  205. Rated 5 out of 5

    Adrian G.

    My pond is 1500 gallons and I have 8 koi and 3 comet gold fish, couple of water lettuce and started with green water and after 3 weekly dosages of your product my pond is super clear and fish are happy, I can see the bottom now ,super pleased with nualgi!

  206. Rated 5 out of 5

    Michael S.

    This spring, I had an algae bloom, the second I have had since I have been a pond owner. However, with Nualgi, it took just a couple of weeks to go from pea soup green, to crystal clear.

  207. Rated 5 out of 5

    Lorraine W.

    helps but not a silver bullet.

  208. Rated 5 out of 5

    Suzi G.

    I was almost ready to fill in my little pond, not fun to sit and look at green water…I stumbled upon nualgi ponds and decided it was worth a try…three weeks in and my pond is crystal clear, I can see every stone on the bottom!!! I can’t say enough about the transformation…I’m a believer!!!

  209. Rated 5 out of 5

    Bill V.

    cleared up fast, fish, snails, tadpoles ,etc. still alive, some string algae on waterfall rocks remains ( toughest to control ), very pleased

  210. Rated 5 out of 5

    Carole G.

    Used Nualgi for three weeks , for the first time in ten years my pond is crystal clear at this time of the year ! I’m ecstatic over this product, I have literally spent thousands of dollars trying to achieve this clarity and this product beats everything I have tried before .
    Thank you Nualgi for your amazing product !

  211. Rated 5 out of 5

    Marc C.

    I added Nualgi POnds it our pond at home it was completely green after 5 days you can see the edge of the pond clear and the plants shoot right up

  212. Rated 5 out of 5

    Jeffrey D.

    After one week my pond is 80% clear and getting better, I’m so happy, thanks.

  213. Rated 5 out of 5

    Amrita R.

    I put the first dose in my pond on Tuesday and two days later I can already see a difference. A lot harder for my fish to hide from me now!

  214. Rated 5 out of 5

    Joe T.

    Finally found something that will keep my pond clear. Working great up to this point. So easy to use and great results. So glad I found Nualgi. Would recommend it in an instant.

  215. Rated 5 out of 5

    K hall

    Nualgi works great. The cleanest my pond has ever been!

  216. Rated 5 out of 5

    Ricky P.

    I love Nualgi Ponds! My water is so crystal clear! Thank you! :­D

  217. Rated 5 out of 5

    Gail S.

    yes this stuff is truly amazing!!! I have used it for 2 years now­­–just ordered some for my aquarium­­­– don’t know why i waited so long!!!

  218. Rated 5 out of 5

    Cheryl B.

    Took 2 weeks but my pond is crystal clear don’t have to put a canopy over the pond this year! Love it!!

  219. Rated 5 out of 5

    Linda W.

    I did have string algae. I did use your product. My algae went away. I did add more plants too. Now my pond is doing pretty good. When I need more, I’ll order.

  220. Rated 5 out of 5

    Jeremy P.

    A loyal customer of The Bloomin Bog Water Gardens in Ilderton Ontario Canada is very impressed with Nualgi only after three treatments.

    The water is clearer then ever before and the fish are happy.


  221. Rated 5 out of 5

    Dewey B.

    Terrific results in our 8000+ gallon pond with a 25 foot fall in 3 small areas!!! String algae completely eliminated in the falls & collection ponds after 3 weeks. Then cleaned the rest of the pond & it’ s now totally clear! So far I say THANK YOU for your product & I will be reordering.

  222. Rated 5 out of 5

    Mary D.

    We have used this for 4 weeks and we can almost see the bottom of the pond (4ft)!!

  223. Rated 5 out of 5

    Gene W.

    This product is amazing ! I started of with pea green. In just one week the pond is crystal clear.

  224. Rated 5 out of 5

    J. Groom “Jagroo”

    I never had a string algae problem in my present pond, but I was having a hard time with green water. My UV clarifier had been going for two weeks this spring, and still green water. You could even see the green particles in the water! Within a week of dropping merely 1ml of Nualgi into a cup of 100ml of water, and dumping it into my 1,000 gallon pond, my water was clear, clear, clear. Not even my UV clarifier could do that job! Amazing! And, I’m sure I have too many fish for the size pond. I’m sold on this product.

    A little bottle will last me the whole summer in 1ml doses! I recommend this product if you’re struggling for clear water! It will change your pond forever!

  225. Rated 5 out of 5

    Jill R.

    My pond is less than a year old, and I experienced a severe algae bloom in the early spring. After spending lots of time and money on recommended algae removal treatments, with no improvement, I stumbled upon an ad for Nualgi on a Facebook water garden page. I ordered it that day as a last ditch effort to clear up my pond. I have used it for 3 weeks ( 1 dose/week) and I am thrilled with the results! I can see the pea gravel at the bottom of the pond, as well as my grayish black catfish swimming down there! The results did not happen overnight for me, but occurred over time…the water is clear, my aquatic plants have taken off in growth and blooms, and my fish seem happy!

  226. Rated 5 out of 5

    BarbaraJo B.

    It has taken a few weeks, but in conjunction with UV filters, and an added screen roof, the water in my 2500gal koi pond is very clear. In the Arizona low desert, this is almost a miracle. Thank you, Nualgi. 🙂

  227. Rated 5 out of 5


    This treatment is amazing, a few days after the first dose the water started to clear. Just finished the the third dose and our pond is 90 percent clear. Have to admit, I was very skeptical but Nualgi is the best investment I have made in our pond. Highly recommend this!

  228. Rated 5 out of 5

    Brian G.

    I have a new pond, and after 3 weeks of settling in I was already getting some string algae around the skimmers and bog. Water was opaque, but all parameters perfectly balanced. I had been dosing daily with bacteria for the first 2 weeks. Once the bacteria was settled, fish comfortable, and no ammonia/nitrites/nitrates, I wanted to get the water clear.
    Several folks on the FB Koi Keepers of America had used and recommended Nualgi. My pond is around 7,000 gallons, so I bought 250mls, which came in 2 125ml bottles. By the time I dosed the second time, I was not seeing any strands of string algae, and by the third dose, I don’t see any green algae growing on anything. The water is transparent and still lightly green/brown tinted, but I can easily see the bottom at 3.5 feet. I have great biological filtration, but no settling tank or bead filter, so it may not ever be “gin clear”. If it does, I’ll put a note back up here. Try this!

  229. Rated 5 out of 5

    Colleen M.

    Started using Nualgi about 4 weeks ago after our Spring pond cleaning. It has kept string algae at bay and the water is beautifully clear. The fish color appears to be very vibrant. I would recommend this product highly!

  230. Rated 5 out of 5


    Waited to post a review to see product results. Definitely see clarity in the pond water. Happy with this product!

  231. Rated 5 out of 5

    Gina J.

    Ok I am a total skeptic when it comes to making pond water crystal clear, I don’t like treating our pond with anything! However we recently moved our pond and it’s in direct sunlight and the green water was winning! I figured I would take a chance since it claims to be natural and less expensive than other harsh chemicals. I put my first dose in on Sunday 4/19 and have been out of town on vacation. A few minutes ago was the first time since getting back that I have had a chance to go check the pond and add the 2nd dose (it says dose weekly) I am truly amazed that my pond IS crystal clear! So for now I am a believer and this stuff does work! My parents pond has always been murky and I am going to try a dose in their pond today to see if it clears their up too! But for now, it’s worth every penny!

  232. Rated 5 out of 5

    Diane R.

    My 1500 gal pond in AZ has 340 days of 80 degree plus temps, sunny and high temps so, I have battled algae for years. So imagine my surprise when this 12 oz bottle of algae control arrived I used the small dropper to add the 1.5 mls of product to my pond. That was 4 weeks ago my pond remains crystal clear with just this 1.5 mls a week being added. Love this product!

  233. Rated 5 out of 5

    Jimmy N.

    Excellent product after one week the water super clear and fish seem happier. Glad I found this!
    Thank you.

  234. Rated 5 out of 5

    Susie F.

    Very happy so far….I have only done 3 treatments but the water is clear and the string algae on the waterfall seems to be lessening.

  235. Rated 5 out of 5


    It’s been two and a half weeks since I turned the uv off and started nualgi. My water is the absolute clearest it has ever been. Water temp has come up steadily in the past few weeks and is now at 65.

  236. Rated 5 out of 5


    I’ve been using Nualgi since Sept. of last year. I use it in two ponds both which have had green water issues. One pond it seems to be working very well, I have had significantly clearer water since I started using it. The other pond I keep water lily’s in and I feed the lily’s pretty heavy, I just don’t think that the product can handle the fertilizer load I put on this pond. I will say that I have noticed a savings on the amount of electricity used since I have not had to run the 110 watt or the 55 watt UV lights since I started using.

  237. Rated 5 out of 5

    Kathy Guraro

    I was lucky enough to meet Anil, the president of Nualgi at the Fresno Koi show. He was kind enough to give me a sample bottle of his product. I put a little in my pond which was soupy green with Algae and within 2 days my pond was Gin clear and I was able to see Koi that I haven’t been able to see for a long time in my Koi pond. I recommend this product to anybody that wants to see their pond crystal clear. Thank you Anil. I am very satisfied and happy with this product.

  238. Rated 5 out of 5

    Pete Tyler

    If you have a pond and having trouble with green water, you have tried everything to clear it up, and have had no success. Then you need to try Nualgi. I had long string algae used Nualgi, cleared it up. My friends have used it, same results. By the way fish are heather and color intense.

  239. Rated 5 out of 5

    Chien H.

    After using it for 6 months and without UV, my pond water is crystal clear! My koi are active and maintain their coloration without using any color enhancing feed. The skin is always shining.

  240. Rated 5 out of 5


    Incredible! This is the only product that has cleared up my ponds and my water gardens. I am especially happy and surprised that my natural pond with no filtration now has clear, clean water with no earthy odor add it always had before. My filtered ponds are getting almost Crystal clear and are cleaner than they have ever been. Thank you to whomever is responsible for this product formulation because the time and money it saves me is a blessing. Can’t forget how happy I am to be able to see my Koi ask the time. Even my lighting in the water stays clean so they shine bright.

  241. Rated 5 out of 5

    The Constant Gardener

    Been using Nualgi in my pond for several months now. Love the look of the water. Haven’t used the UV for months now. A great new product.

  242. Rated 5 out of 5

    Ladyann H.

    My pond is crystal clear now, less filter cleaning, healthier happier fish. Thank you Nualgi

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