My tiger barbs have started eating algae off of the suction cups of my heater and were kinda pecking at the top of my driftwood like looking for food. They do normally peck at the gravel all day long, though. Do they just do this to stay busy, or am I not feeding them enough? I feed them a small amount of pellets twice daily. With frozen brine and blood worms two or three times a week. (like a 1/3 of a cube at a time) They eat all food within 30 seconds, and I don't give them more. It's Probably 2 or 3 pellets each. But even with a few pellets, their stomachs look full, or at least bigger, so that's why I only have been giving a few.