I recently got a couple of pygmy cories (my first ones, and I am now obsessed with them). My tank is relatively clean, so I bought them sinking algae wafers. I put one in and left if for a couple of hours (per the instructions). I expected I would have to remove the uneaten portion (even though the wafers are less than 1 cm diameter). But, it was gone...and all my rummy nose tetras (the only other fish in the tank) had protruding bellies! Today, after I fed the tetras their flake food, I broke off a quarter of a wafer and nestled it down in an (artificial) plant for the cories to find. The tetras were immediately hovering around it. I come back to see one tetra with a giant belly again. These tetras are like Labradors; they will eat everything! And I can't imagine it's good for them to gorge themselves to the point of protruding bellies. So, my first question is this: How do I feed my cories without the tetras eating their food? Or should I just let the tetras eat the wafers and not feed them the flake food? Second, today there is a small portion of the wafer left (it's been in there about an hour). It is now nestled into the gravel a bit. Should I leave it there for cories (or likely the fatty tetras, who are still picking at it as I type), or get it out? I don't want to pollute my water with uneaten food, or overfeed the tetras, but I want the cories to have something to eat! Any tips on using sinking food (and not having it dirty up the water) are welcome, as I've never had bottom feeders before. It's not clear to me how much I should be using. (FWIW, I have three pygmy cories and three rummy nose tetras. Don't worry, I'm going to get a bigger tank so they can be in bigger groups!) It also seems to me that gravel and sinking food aren't too compatible (it gets lost in there). Thanks!