Oh, and they do tell whats in it now, and its nothing like peroxide. It uses "chitosan" which is a polysaccharide derivative that is made from chitin, or the protein that comprises crustacean shells and insect shells. It is bacteriostatic and as mentioned above it will kill of good and bad bacteria.

My opinion is that if you have needed florashield before, then you should just start each grow with an innoculation of beneficial bacteria, I use Botanicaire's Hydroguard, and you will likely get better protection from root rot and from buildup on your plastic parts.

For cleaning between runs, nothing beats bleach, plus it evaporates when you are through leaving no risidual chemicals except for a small amount of sodium chloride.