Many do it in the morning or just after lights out, but I feed later in the evening, but before the lights go out (convenience). They still open up and eat. An advantage to feeding after the lights are out (or before they come on) is to avoid harassment from fish. I use a plastic bottle top to feed them. I cut it out and place it over the frags and feed through the opening. Lets them eat slowly without fish being able to pick it off. HTH