Real Clear Results with Nualgi AquariumsTestimonial from Fresh & Saltwater Aquarium Owner Christian D.RubenTankWeek2Credit Everyday Aquarist W. Planted Tank beforePlanted freshwater tank trialing Nualgi Aquarium

Nualgi Aquarium Freshwater

4.93 out of 5 based on 28 customer ratings
(28 customer reviews)


Engineered to supercharge your freshwater aquarium's nitrogen cycle and give your bio-filter a boost, Nualgi Aquarium is easy to use, efficient, and yields rapid results – try it today!

SKU: nualgi Categories: ,
DID YOU KNOW? According to a 2015 study by the scientists at the National Marine Aquarium, watching an aquarium can lower your heart rate, help reduce high blood pressure, and improve your mood.

Product Description

You Can Also Try Nualgi Aquarium for Saltwater Tanks

We all know there is no such thing as a silver bullet for maintaining a healthy aquarium… but we have engineered an innovative water treatment for aquariums which will supercharge your tank’s nitrogen cycle and make your bio-filter more efficient. The result: Crystal clear water with increased oxygen levels and healthier plants, coral, fish, and crustaceans. Try it and see for yourself!

Bottle Size Recommended Tank Size Cost for Full 8 Week Cycle of Nualgi
Fresh Salt Fresh Salt
4oz     15 – 60 Gal      20 – 85 Gal $14.99 / 60 Gal $14.99 / 85 Gal
16oz  60 – 240 Gal     85 – 340 Gal $39.99 / 240 Gal $39.99 / 340 Gal

When You Supplement Your Routine With Nualgi, You Will…

  • SEE MORE –  Reducing nuisance algae growth on glass and in your tank, Nualgi improves water clarity and visibility to reveal more of the tank’s environment and its inhabitants.
  • FEED LESS – By restoring missing nutrients, Nualgi 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 corals!
  • CLEAN LESS – Nualgi controls and prevents the growth of nuisance algae as diatoms produced by Nualgi out-compete bad algae for nutrients and increasing dissolved oxygen (DO) levels, improving water quality  –  fewer water changes!

  • WATCH YOUR TANK FLOURISH – Nualgi Aquarium will significantly improve your coral and fish health and longevity, and our trials have shown Nualgi Aquarium can kick start new coral growth in as little as 1 week!


How Nualgi Aquarium for Freshwater Works

Additional Information

Weight 3 oz
Dimensions 6 x 3 x 9 in
Bottle Size

1oz, 4oz, 16oz

28 reviews for Nualgi Aquarium Freshwater

  1. 5 out of 5


    What an amazing product! And all natural too! I run a high tech planted discus tank, And without Nualgi I know I’d be fighting a daily battle with algae. Keeps the water crystal clear and enhances plant growth. Fish are happy and healthy.

  2. 5 out of 5


    I was skeptical that Nualgia would achieve all it claimed and was super excited when my algae started disappearing! In my 12 week trial it eliminated all the algae I had been battling for months. I highly recommend this product for anyone looking to rid their tank of all types of nuisance algae in one simple step!

  3. 5 out of 5


    The Nualgi worked amazingly. I have a planted Discus tanks with swords and it was refreshing to not have to dose the multiple bottles I usually have to dose. Would recommend this to anybody who asked, even recommended it to the owner of the pet store I work for.

  4. 5 out of 5


    I will not go without it ever! It’s magical!

  5. 5 out of 5


    I’m not normally compelled to review a product, but this Nualgi stuff really surprised me. I bought the trial bottle a few months ago, at the time my tank was looking a little rough; I had cyano, a couple of rocks with a bit of hair or turf algae on them and I was cleaning my glass every day or 2. I filter my tank exclusively by Algae scrubber and have always been relatively happy with the results, I wanted to see if this product would complement or compete with my scrubber. The price was right so I figured why not give it a try.

    When the product arrived I read their recommendations which included reducing the tank temps, and shortening the photo period. At this point I figured the product was Bull$hit, and I probably just bought a bottle of distilled water or something.

    I dosed my tank per the instructions ( I did nothing to my tank with regards to light schedule or temp) and started to get a diatom bloom, I then started dosing 1/2 of what they recommend also per the instructions. To my surprise my algae screen growth exploded, the mass of algae that always grew on top of my powerheads and locline started to disappear, the slime went away and the diatoms cleared up.
    This happened over a time period of about 6-8 weeks.

    When I bought this stuff, I was incredibly skeptical. I only bought it to support a new sponsor who was offering a good discount, I never really expected it to work, but I’ll be damned if it didn’t.

    During this time I siphoned nothing, and changed nothing with regards to flow, lighting or feeding. I am sure the cyano would have cleared itself up by now without the Nualgi, but the pockets of algae that grew on my overflows and powerheads have been an issue since I set my tank up a few years ago and for the first time I am not cleaning them every couple of weeks. I’ve only been cleaning the glass about 1x per week for the last month as well. Sure I still have some algae but all in all, I am of the opinion that this stuff works.

  6. 5 out of 5


    I love the product but it gets expensive with a 180 gallon tank.

  7. 5 out of 5


    Great product.

  8. 5 out of 5


    First of all, this review applies only to my densely planted tank, not to a salt tank or a bare glass tank. While the product does NOT eliminate all algae (in particular, you might need American flagfish to handle small amounts of surviving hair algae), I still decided to give it 5 stars because it’s the best product on the market for the purpose, without being expensive to maintain like a UV sterilizer or poisonous like algicide. Definitely, for best results, use an ammonia remover in if your tap water contains ammonia as part of chloramine treatment, because excess ammonia following a water change will enrich algae. I used 1.5 mL of this stuff every 4 days for 12 days in my 40-gallon tank, and it heavily suppressed my waterborne algae problem, which otherwise would have been obvious in less than a week. But the main reason for the 5-star rating was: After a week, I had a modest amount of hair algae on the glass, even though the tank was otherwise nearly clear. When I scraped it off into the water, the water of course immediately turned a tinge of green. But 2 days later, it was back to being nearly clear. The only weird effect has been the accumulation of small greenish dots on the water surface. I don’t know what these are, but they seem to be harmless and in any event occupy only a small fraction of the surface. It seems like nonsense that only 1.5 mL of this stuff every 4 (or up to 7) days can achieve such effects, but I have to admit that it worked in my case. The reduced time and water waste is well worth the price. (After 12 days, my tank looks like it usually does on day 2 or 3.) My only complaint is that it seems to contain phosphorous, which is completely unnecessary because fish food and tap water and generally loaded with it to begin with.

  9. 5 out of 5


    Nualgi is an awesome product, one that does everything it claims and does it very well! I’ve been using Nualgi for over a year, and, I’ll never go without it in my fish room!

  10. 5 out of 5


    Nualgi is an excellent alternative to many forms of algae control on the market today. In an era of exploding information in this hobby I have found Nualgi to be a very useful tool in controlling nuisance algae in both marine and freshwater aquariums with a relatively good rate of success. Also, the support by the company is outstanding. Definitely worth a try.

  11. 5 out of 5


    Interesting product, quick delivery, clear instructions. I’ll post an update when I see how it works.

  12. 5 out of 5


    I’ve had the pleasure with Nualgi and their products for a year now and have been impressed. Nualgi Aquarium and
    Nualgi Pond flat work. I been keeping fish inside and outside for almost 20 years. All fish keepers have their special quirks, Nualgi is mine!! The last ten of my professional life is keeping antibiotic and chemical use down in all kinds of production animals, so finding a product that WORKS the same way in my aquarium and pond is a wonderful find. All we can ask from a (any) product is that it works at the level instructed and all the time. I urge all keepers of any type of aquarium or pond to use this product with the right type of microbial product together for a month and you’ll know why I won’t keep fish without it.

  13. 5 out of 5


    Great Product.

  14. 5 out of 5


    Good stuff.

  15. 5 out of 5


    I am entirely satisfied with the product. I will order Nualgi in the future, and recommend to others.

  16. 5 out of 5


    Works great so far.

  17. 5 out of 5


    Thank you!

  18. 5 out of 5


    Excellent product. Will use this on all my aquariums.

  19. 5 out of 5


    Product seems to be hard at work on algae I have been struggling to control. I had gone with no lights and that wasn’t doing the trick. This product is easy to use, and was a great find.

  20. 5 out of 5


    See any algae? Of course not, Nualgi works awesome. It’s amazing. I used to have algae all over my plants the gravel the glass it was terrible.
    And then I tried Nualgi.

  21. 5 out of 5

    (verified owner):

    This product surprised me at how quickly it began working. My 55 gallon freshwater tropical aquarium has timed LED lights that are great for plant growth. But a side effect that’s common w/ the LED’s is massive growth of hair algae. It’s nasty stuff to look at covering attractive rock, wood and gravel features. It also gets all over your plants. I used this stuff about 2 weeks ago according to the directions. A week went by and I daily thought my eyes were playing tricks on me. Now I’m convinced it works. There is now far less hair algae on the rocks. In this 2 year old tank the colors on the rocks are again visible, in some areas the algae is nearly gone! On the wood the algae is now much smaller. None of my fish eat that algae so I don’t know what’s eating it, perhaps the diatoms as the description claims. In addition the fish remain healthy and in good color. Being that it’s only been 2 weeks we’ll see how it continues over time but so far it’s incredible.

  22. 5 out of 5

    (verified owner):

    I had an algae problem in the form of a brownish-green slimy gum which clogged up my pump and filter requiring cleaning every four or five days. A treatment with Nualgi Aquarium solved the problem… with no ill effects on my fish. Perfect!

  23. 5 out of 5

    (verified owner):

    Now I don’t have to scrub the aquarium wall every week. I’m doing it every month now. It helps maintaining my aquarium clean. Thank You Nualgi

  24. 5 out of 5

    (verified owner):

    Works great

  25. 3 out of 5

    (verified owner):

    This time around I haven’t had the results I would have expected yet. Using a walstad method planted tank and I’m still seeing lots of algae growth on the backglass.

  26. 5 out of 5

    (verified owner):

    I am stunned by how well this works. Last year, the first year I had my tank set up, I almost gave up due to battling black hair algae, brown algae, and green spot algae. My battle with the BHA resulted in dead plants and fish. After that, new plants developed green spot algae and I had to throw them away because I couldn’t get rid of it and it looked awful. Nualgi was my last hope when the green-spot algae showed up again on new plants, even after cutting back on lighting and ferts. After 3 weeks of dosing Nualgi (starting in March of this year), it seemed to me that the GSA was thinning. After 6 weeks, I was certain. Now it is gone! Another benefit of Nualgi is the Cryptocoryne, that always showed some melt after a water change, is so lush and beautiful and the leaves never melt. When I do a weekly water change, I dose Nualgi and Leaf Zone. All the plants in my tank are healthy and beautiful. I can’t recommend Nualgi enough. Have patience, results don’t happen overnight.

  27. 5 out of 5

    (verified owner):

    Happy aquarium and happy me with this . Awesome . I refer to all beginner with parameters issue . Little of this a week and resolve all your problem

  28. 5 out of 5

    (verified owner):

    Great product I’m see improved water clarity and the brown algae is beginning to die off two thumbs up

Add a review

Your email address will not be published. Required fields are marked *

ATTENTION SHOPPERS, Prices on all sizes of Nualgi increased on January 1, 2021.