Okay, so in my 38 I have two fish that always have big fat tummies because they eat all the food. I can't fast them because the "competition" needs to eat! It's my bumblebee catfish and my betta. The catfish is hogging all the food from my cories and snails, and the betta eats everything. I can't even drop in a veggie wafer without her eating half of it. How can I make sure my other fish and the snails are getting enough???