Nualgi Ponds – Natural Algae Control + Water Clarifier

Rated 4.63 out of 5 based on 259 customer ratings
(273 customer reviews)


Use Nualgi Ponds™ to naturally balance your pond, control algae growth, and get crystal clear water you and your fish will enjoy more!

SKU: nualgiponds Category:
WHOLESALE DISCOUNT – buy a total of 12 bottles or more and receive Special Wholesale Pricing. To apply to the program and view pricing info, go sign-up for our Wholesale Pricing Program.


How Does Nualgi Ponds Work?

Within 3 – 5 hours of applying Nualgi Ponds, a bloom of Diatom algae (the good kind!) will develop. The diatom algae bloom out-compete nuisance algae for CO2, N, P and other nutrients, causing the bad algae to die off. It then locks away some of the harmful nutrients in the new bio mass that is consumed as live food for your fish and zooplankton. The growth of diatoms provides oxygen to bacteria who in turn clean up the waste products of fish and leftovers. The exponential growth of diatoms provides oxygen to bacteria who in turn clean up the waste products of fish and leftovers. This natural process helps clean ponds and make their water sparkling while helping reduce bad odors.

What Are the Benefits of Using Nualgi Ponds?

  • NATURAL ALGAE CONTROL FOR PONDS, WATER GARDENS & FOUNTAINS – Control algae growth and clear green water – without toxic algaecides or expensive UVs!
  • IMPROVE WATER QUALITY & CLARITY – Safely restore missing nutrients & balance your pond’s chemistry for improved water quality and crystal clear water!
  • ELIMINATE OFFENSIVE POND ODORS – Supercharge your pond’s Nitrogen Cycle and puts beneficial bacteria to work cleaning up waste & pond sludge.
  • PROMOTE THE GROWTH OF DIATOMS & ZOOPLANKTON – The diatoms fueled by Nualgi are quickly hunted down and eaten by zooplankton – the preferred live food for your fish!
  • ENHANCE FISH HEALTH, COLOR, AND ACTIVITY – Koi pond owners will see their fish be more active chasing down their free food while health & color improve from a more balanced diet and overall ecosystem.
  • IMPROVE AQUATIC PLANT HEALTH & GROWTH – Water gardeners will see all their aquatic pond plants flourish once your water chemistry is balanced and missing nutrients restored.
  • INCREASE DISSOLVED OXYGEN LEVELS – For many eutrophic ponds, results may be visible by afternoon on the first dose – starting with the bubbling up of oxygen you can see!

How Many Gallons of Water Does Each Size of Nualgi Treat?

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
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273 reviews for Nualgi Ponds – Natural Algae Control + Water Clarifier

  1. Rated 5 out of 5


    Does the job
    Works Great.

  2. Rated 5 out of 5

    James H.

    Best Ever
    My pond always had a tea color. MY water is now crystal clear

  3. Rated 5 out of 5

    Gregory Anne Cox

    Pond management is much easier
    We have been using Nualgi for 4 weeks now and our pond is getting better and better. And it also claims it helps with fish health, well, we have had 3 loads of fry since we started using it. Not sure it’s related but they are also looking good. Totally recommend this product. We have had way less string algae even though it’s been hot and there is less gunk overall clinging to the sides. Buy it!

  4. Rated 5 out of 5

    David Bates

    Like many preceding reviewers, I too was skeptical of this Nualgi product’s effectiveness but out of desperation, gave it a try anyway. My moderate sized (3500 gal) koi pond I built 20+ years ago, cleared for the first time after 3 weekly doses despite it being significantly overstocked (which I am rather ashamed to admit ). Obviously I will continue to use this effective and environmentally safe Nualgi product and strongly recommend it to other.

    • nualgi (verified owner)

      Thanks David, we appreciate you taking the time to review Nualgi and share your insights. Please consider sharing a photo sometime to our Facebook page or our upload page –

  5. Rated 5 out of 5

    Lauren L. Burke

    It works!
    This product works! Fourth dose was added four days ago. Came home this afternoon and can see the bottom of my pond. The water is nearly perfectly clear. It was solid green before I tried this.

    • nualgi (verified owner)

      Thanks for your feedback Lauren. This is great to hear. Happy Ponding!!

  6. Rated 5 out of 5



    Was skeptical, but my UV filter light bulb broke and I am fed up with cleaning the UV filter and replacing the very expensive light bulb. In 4 weeks, I suddenly noticed I could see the bottom of the pond perfectly!No effort, very little expense compared to a UV filter. Amazing.Now I am dropping a tiny amount in my 10-gal. house aquarium to see how it works–just as an experiment.Thank you!!!!

  7. Rated 5 out of 5

    Jason / 4 minute tech

    Finally the Holy Grail of Pond control
    Finally the Holy Grail of Pond control
    To be honest with you I was skeptical after trying multiple things. I had to stay organic as the fish that’s in my 10,000 gallon pond are food fish tilapia. I was using peroxide for a while but that would kill off a lot of the good bacteria. Ultimately tried out Nualgi and I have to say I’m very impressed and I definitely will be using this product from now on. I no longer have to worry about a green pond or fish dying from wacky numbers like pH and nitrates and all that jazz. Thank you!

  8. Rated 5 out of 5


    Truly Great Product for Koi Ponds!

    I have had a koi pond for almost 20 years. Until 2016, I struggled with algae control, water quality, plant health, and needed to regularly manage water chemistry (pH, nitrates, hardness, etc.). In 2016, I decided to try Nualgi, as I felt like I was losing the algae battle, nevermind the rest of the list. This is my third year and I have to tell you Nualgi has changed my world. It is miraculous! The string algae is gone, water clarity has never been better, the plants are the healthiest they have ever been, and the fish are multiplying! When I clean the biofilter, there is almost nothing in it! I have thrown away all my chemicals and water additives. This morning is my regular weekly day to add Nualgi and I noticed there is ZERO algae in the waterfall! It is really iimpressive. It remains very important to keep chlorine and other antiseptic chemicals out of the pond, so when I add water I use a hose-end chlorine filter on the garden hose. Also, I turned off my UV filter as suggested. But that’s it. No other additives whatsoever!

    I am not sure why there are one star reviews claiming Nualgi is a waste of money. This stuff is the BEST INVESTMENT i have ever made for my pond and waterfall. Awesome. (And the fish and plants have never been better…)

  9. Rated 5 out of 5

    thomas martin

    This product is amazing I started dosing back in June on my 5th dose now my pond is clear and I can see straight to the bottom Thank you nualgi for a great product.

    • nualgi (verified owner)

      Thanks for the review Thomas! Great to hear you and your pond are loving Nualgi!

  10. Rated 3 out of 5

    Donelle Cushing (verified owner)

    Dose 4 this morning. Doing the 10 % water change on Friday mornings then dose Saturday early morning. Still no change in the beautiful bright green water, I do nit nor have I had string algae just this hard to get rid if single cell… In going to continue treatments in hopes that it will clear my water, I miss seeing my fishies

    • nualgi (verified owner)

      Stay patient Donelle :). You could dose every 5 days instead of 7. In problem ponds, you could also dose Microbe-lift PBL twice per week according to their instructions. Once improvements start you can go back to regular dosing of Nualgi. Stay in touch, we’d like to you to see your fish too!

  11. Rated 5 out of 5

    Dar (verified owner)

    I tried this last year in my 3300 gallon pond. Did not have a great result. I had to use an algaecide to remove the string algae. It was pretty much an ongoing battle. This year I made some changes and cleaned grass etc. away from the edge of the pond. I vacuumed and manually skimmed the pond. I also flush the pond out a little every week. I started using the product about 1 month ago and I am pretty impressed with the results. Not one bit of algae so far and it has been very hot. I have a lot of lichen on my rocks and that is being reduced as well. I did notice when ever I dosed the pond it seemed to put the fishies in the “mood”. There was an awful lot of spawning going on. A koinkydink maybe, but awesome product. My fish are far more active then they have ever been and my water is getting clearer all over he time. And my pond does not smell like a static tank. Thanks Nualgi. I wish Canadian stores would carry this.

    • Anil Nanda (verified owner)

      Thanks Dar. When you improve oxygen levels in the pond the fish can get in the “mood”! When animals feel secure, they spawn. We have many users tell us about spawning when using Nualgi. In aquaculture ponds, we have seen numbers grow from 50k fish to over 100k on maturity. There are stores in Canada carrying it. Please contact for list of vendors near you

  12. Rated 5 out of 5

    Jesus L. Opiana (verified owner)

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

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