Hi All, i have 10 cardinal tetras, 2 guppies and a thick lip gourami. I feed them half a frozen brine shrimp cube twice a week as part of my dry food rotation. My question is, is half a cube too much for the amount of fish I have? They seem to eat it all un about 5 minutes but the tetras bellies look big after feeding and they're not very active after eating. Thanks!