Not much to say it's ammonia in a bottle, helps start up a tank without fish and you know what the ammonia will be. Typically people use pinches of fish food, which can take hours/days to even begin to release ammonia and the amount they release aren't really equivalent to potentially the amount or type of fish going in anyways. Used it on two tanks with no losses from water, had 1 loss which came with some sort of sore on it from the store. Took roughly 2-3 weeks for the full cycle from start to finish but that was with a hand full of low percentage water changes and dosing quick start and fritz zyme 7.

We recently updated some tanks and I had to cycle the tank, but I hate using fish to cycle a tank, especially bettas. Fritz is my go to for everything fish related. this stuff had my moms "desk buddy" (her tank on her desk for work) tank cycled in less than a month.

Buy it if you want to cycle a tank quickly and need to move some of your loved ones to a larger tank. Highly recommended.

Here are some details of my most recent comedy. Please laugh, it's good for you!
I received 2 comets as a Christmas present from my neighbor. I fish-sat for her gold fish over T-day and commented that I did some research - having a sole goldfish is illegal in Switzerland ( inhumane there - must have at least 2 since they are social creatures) and that I missed the greeting I got every morning when I walked into my home office. Hence the comets - in a 2 1/2 gallon bowl! I added some amazon fern and a marimo ball, a small filter ( BF5 ) , bought a test kit. After the first ammonia spike days after getting these guys - in came ammo lock, daily water changes, gravel vacuum, panic attacks galore. In the meantime they've both doubled in size. So I bought a 10 gallon kit as the middle school for them.
I have simple gravel, resin log ( I couldn't add any more dimensions to this equation with real wood ), more ferns, crypts, an anubia and more marimo balls. I started feeding flakes to the fishless tank and got no response. Nothing. Perfectly clear water with gravel, log and plants.
I've been watching KG Tropicals videos and they recommended Fishless Fuel and Fritz Zyme 7.
My tank is now mid-startup. I have ammonia from the Fuel, nitrites, and nitrates. Waiting for Zyme7 to corral the ammonia and nitrites. Once they drop then Minnie and Pearl are going in. I'm hoping for only a year. Then on to a 60? 125? I live in Jacksonville FL. How about a pond on my back porch?
Anyway, great products. Panic is less frequent now that I have quality products on my side.

It took my tank a moth to do a fishless cycle, which is what was expected. The way to go to cycle a tank.

My LFS always tries to recommend cycling with fish, which I do not agree with. My last tank I tried a fishless cycle by "ghost feeding" and it took around 6-8 weeks for it to cycle properly. Not bad necessarily, but it's hard to tell how much food is needed to provide enough ammonia. I decided to give fishless fuel a try to set up my 29 gal bio cube. After reading a lot of reviews, I decided to do a half dose. This kept my bio cube spot on at 2 ppm ammonia. It fully cycled in 7-10 days. Would definitely use again in the future!