API QUICK START Freshwater and Saltwater Aquarium Nitrifying Bacteria 16-Ounce Bottle

Works. It helps to establish the tank over time. There’s no instant cure and you cannot get fish or axolotl or anything in a tank with out any cycle. Wait for it to cycle. Use this. It works well. It takes four weeks to cycle.

My old aquarium started leaking at the sides so I had to replace it in a hurry. Besides using the same filter media in the new tank that was used in the old tank, I started from scratch with everything else in the tank. I bought this Quickstart product in hopes I can avoid going through the long cycling process that's hard on fish. After filling the new tank I added the amount stated on the bottle, and adding a smaller amount with each weekly water change. It's been about a month and my new aquarium has remained crystal clear the entire time without any signs of bacterial bloom or cloudiness, I've also been using water test strips and so far the water quality has remained good. While I'm sure using previously used filter media helped, there have been times before when I've upgraded to new tanks and the water still would become cloudy even with a previously used filter so I feel like this product definitely made a difference. I originally purchased it to help with the initial cycling but now I plan to continue using it when doing larger water changes or when replacing the filter media.

Works fast, keeps ammonia and nitrite in check, and makes new tank setups stress‑free. Great for both freshwater and saltwater. Highly recommend.

Works as it should

Doesn't seem to last for long. It'll do great for my tank to seem like it's cycled for about a week until everything is off again and then I try to come back. It's weird maybe it's a temporary chemical change but it doesn't seem to stick. I'm following all the rules about not washing my filter media and tap water and doing things to maintain the balance of the tank and not overfeeding etc etc. I'm giving it 4 stars because it's literally the only thing I've been able to do to even come close to cycling a 3 gallon tank. 💔

Gives confidence for fish health

Keeps my betta happy and colorful

The API QUICK START for freshwater and saltwater aquariums is a total game-changer—especially if you're setting up a new tank or adding fish to an existing one. It makes the nitrogen cycle process way less stressful, both for you and your fish. I used it when starting a new freshwater setup, and within 24 hours my tank was safe and stable. No ammonia spikes, no nitrite issues—it genuinely helps establish the biological filter FAST. It's also great to use after water changes, adding new fish, or cleaning the filter. What I love is that it’s super easy to use—just shake and pour. The bottle gives clear instructions, and the results speak for themselves. My fish were active and healthy from day one. This is one of those products you always want on hand. It helps create a healthy environment and gives peace of mind whether you're a beginner or a seasoned aquarist.

Its good to rapidly reduce ammonia

Highly effective Improves water quality by maintaining bacterial colonies Easy to use... Rather than other products. Must to stepup a new tank.. also it is good to add once in month so replenish the bacterial colonies

Good

Great price quality first class

Very good but know your water chemistry and what you want to achieve.