1. Never used it but plan on it. Many in the local fish club swear on useing a bottle on newer tanks to get the boost before clean up crews go in and have advised me that it helps even after that if you just toss in a dose a week.
2. Once a day, I'd guess anywhere within a couple hours is ok. Myself I do all my fishy chores the second I get out of the shower after work.
3. It won't have an effect on the cyno directly I don't think. I took a very cheap way out of my cyno problem,I bought this phosblock filter pad at my
LFS for $8 and cut a little chucnk out of it every 2 weeks or so and use it as a prefilter media. It wiped out my problem in 2 weeks the draw back is it gives you a false very high
ammonia reading on all the tests I've tried so that kinda becomes a guess unless you let it clear itself from the system.