Of my four tanks the only one I have cyano issues with is the one that has only snails and no crabs? Now that I do not have any SPS in there I may try the Chemipure Elite. I also have a MP10 on it so I know the movement of water is not an issue and my TDS is 0 from my R/O system. Maybe we should start a new thread on snails and cyano or who eats snail poop?