Fritz Aquatics FritzZyme 7 Live Nitrifying Bacteria Naturally Removes Amonia & Nitrite for Freshwater Fish (16-Ounce)

This stuff always works for me, especially if I have light stock in my tank. I do fish in cycles all the time and never had any issues with fish dying on me thanks to this product. You could prevent ammonia, nitrite, and nitrate spikes by adding like 4-5 small fish to your aquarium. Don’t add too many fish! More fish means more waste, which your new system won’t be able to handle. Add easy aquarium plants (Hornwort, Salvania minima, Brazilian Pennywort) as many as you can. You need plants plus this product for a successful fish in cycle!

When I first set up my aquarium, I started with Seachem Stability. However, after 2 weeks, my nitrite levels still hadn’t reached zero. I decided to switch to FritzZyme because it contains live nitrifying bacteria. After I started using it, my tank finished cycling during the third week. I honestly wish I had started my aquarium with FritzZyme from the beginning. If you’re looking for a product to help establish the nitrite cycle in a new tank, I highly recommend this one. Just make sure to follow the dosing instructions on the bottle for the best results. And ease of use.

This was effective for me. I did a fish-in cycle, used some lightly seeded media and gravel from another tank and then used this bacteria and dosed with Prime everyday for a few weeks. The cycle was finished pretty quick, taking about three weeks rather than the normal six or so, and I didn’t loose any fish and they all looked healthy and happy throughout. I tested my parameters regularly and had only mild spikes in levels before it colonized. I was always skeptical of bottled bacteria but this one seems to work quite well.

I made a mistake....I believed the reviews!! The review said that upon opening the bottle of FritzZyme 7 and it smells like rotten eggs or sulfur it has gone bad. So when I opened mine it smelled like rotten eggs, so what did I do? I returned it and got another. The new one smelled the same way. So on my way to return this one I stopped by Ocean State Aquatics to ask the professionals because this is what they use. They said it should smell and if i doesn't IT IS BAD!!!. So let it be a leason to you and me, do not believe everything you read in the reviews!!!! If you don't beleive me and Ocean State Aquatics read the label on the back and it will tell you the same thing!! DUH!

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.

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.

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.

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.

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.

Al parecer este producto es muy bueno y cumple con lo que se describe en la página y en las revisiones que se hacen de él, sin embargo lastimosamente llegó a mi casa con la fecha de caducidad expirada hace un año. Si se vuelve a plublicar, seguro lo compro.