Fritz Aquatics FritzZyme 7 Live Nitrifying Bacteria Naturally Removes Amonia & Nitrite for Freshwater Fish (32-Ounce)

Saved my fish tank. 300 guppies lived when their tank started to leak and they were thrown into a new tank with no preparation. Started to crash and this stuff saved it ( with a lot of water changes). Easy to use. Well worth what I paid. Highly recommend.

I’ve used this on my tanks and friends’ tanks with struggling eco systems, it is WORTH IT! Soon after adding it, you start seeing the micro organisms responsible for keeping your water clean and your filter working well. I would recommend this to any aquarist as a basic need.👍

If you wanna get your fish tank bacteria this is the stuff to use.

My concern were the reviews that said it had “ammonia”. However, most tap water has ammonia, mine does. So I cannot test this product using tap water. Or else it would give a false positive result. Also, the smell of “rotten eggs” is a byproduct of bacteria “sulfur” - so it’s normal to smell this. For the test. I used a sample of water from an established tank that already has 0 ammonia and added FritzZyme 7 to it. Using the API ammonia liquid test, results are FritzZyme 7 does NOT contain ammonia. Looking forward to how this works on my tanks that need a fortification of BB. UPDATE: 1 week later, decided to use it on a newer tank to test its full potential and it cycled (day 1: 5/28/25 and today 6/3 final results)! Amazing! Tip, if doing IN-Fish cycle, make sure to watch any spikes in ammonia, nitrite, nirate, or PH daily. If needed do small WC, don’t mess with the substrate or filter when doing so, and let the cycle do its thing to keep your fish safe. Trust the process. This product did what it said it would do. Using it now to fortify my other tanks.

So seems like a great product but I would like to do another cycle with it because I did squeeze a cycled sponge filter in new aquarium but that being said I used this every other day and my aquarium was completely cycled in 2 weeks and now has fish in it so im very pleased. I will be buying another bottle for a 55g im setting up in a month.

Works well, but I did not realize I needed to buy the saltwater version. So if you have saltwater look for the saltwater version.

I do not know exactly how much good this product does for my two fish tanks. What I do know is that for many years I have added it every 2 weeks (tank cleaning) and the results are my fish losses have been minimal.

This is my first time using this product. The reviews spoke highly of this company. I started with ghost feeding the first week, but wasn't getting as much ammonia as I wanted to begin the cycle. I got the ammonia that goes along with this bacteria in a bottle. Got the ammonia up to 4ppm 2 nights ago. Yesterday, this bottle came in, and I dosed it as recommended. This morning I did my tank parameter testing with the API Master Kit. In my cycling tank it read 2.0ppm ammonia, 0 nitrites, and 5.0ppm nitrates! It just skipped right over nitrites! That tells me this product is VERY effective! Considering it's taken me months to cycle other tanks, this is mind blowing to me. I'm glad I listened to experienced folks that using high quality ammonia and live nitrifying bacteria is FAR superior to ghost feeding. I purchased the smallest bottles they have, and I'll still have nearly all of it! Well, I guess that means I'm just going to have to get more aquariums, ha! It's so easy I'm still processing this. Don't sleep on these products, the value far exceeds their price! I'm also glad this can be used as a maintenance for established tanks. It will be a great product to have on hand to maintain a well functioning cycle.

Brilliant

I emailed Fritz about some quries and their response was prompt and friendly. been using these for tanks and i do not need to add any salts or whatever. Fzz7 will stink like old eggs and a bit brownish but it is normal, not spoiled. Fritzguard is bluish and dun need it as much as Fzz7. Keep them normally in cabinet and use them every water change. Instructions are clear..

El producto llegó caducado.

I tried quite a no of other bacteria for my fish tank and found this to be the most effective. Only a small amount is needed for a stabilised tank.

Absolutely rubbish, please don’t buy this…buy gloop instead for the live bacteria…these don’t work.