I have a zoolanthid (sp?) and another coral pictured here. I bought some "PhytoPlan Advanced Phytoplankton Diet" but I am unsure how to feed them exactly. I have a pretty small tank, it's 20 gallons and I have a marine betta, humu, clown fish and a cowfish. I know the cowfish is going to outgrow my tank very soon but when I bought it the guy said it wouldn't grow much (I don't go to that store any more). Also, I plan on upgrading to a 90 gallon in the next 6 months or so, so I'm going to try to hang onto the cowfish if he can make it that long in here. I got the corals from the same store and he said don't worry about feeding them, they'll filter what they need out of the water. They haven't been looking quite as healthy latelt so I checked with another store and I bought this PhytoPlan stuff just now. Do I just drop a little into the water and it'll go where it needs to go or should I drop it directly on top of the corals?