interesting, never realized how much of a problem this can be. i have it in my fuge, and it has haulted the growth of the green macroalgae by shading it from the light. however, in my 180 display i don't have any of it. i've got 3 tangs, a sailfin, kole, and regal, as well as turbo snails (although, not sure if they are mexican or not). i am having high nitrate issues and was looking into making a bigger fuge. maybe i'll try clearing all cotton candy from my existing fuge first, then add a snail or two.