Hi..first off, I'm not an expert..I am cycling my first nano reef as we speak. I have done a lot of research on this and many of the nano reefers use it in their cubes. Are there guarantees? I don't think so, many of the nanor reefers swear by it......but...a lot of what we do is an art...sorta like surgery or medicine.....you have to pick something and go with it and see what results you get. I plan to add it to my tank after the cycle ends and the activated carbon supplied with my tank is ready to be changed. If my parameters stay great...then chemi-pure stays in. Good luck SH