Nitrate is 0 phosphate is 0. Wat da heck man! I thought algae only feeds on these two. What other thing that I needs to survive in a tank? I would turn off my lights buy my corals need it. Don't make any sense! Can silica feed algae also? I doubt I have any silcia in my tank because I use my local petstore R/O water. Grrrrrr.. Its an never ending battle with algae...Who has a grenade? Ima throw it in my tank.. THe algae is so annoying.