Oh,Fishdud, I don't know if I want to mess around with that. One thing I don't do is remove any algae from the back and side glass, not that there is really anything visible, but it is there. I think probably the best bet is to put the food in after lights out and take our chances. We could observe them for awhile and if their bellies are getting plump than I guess it would be working. It's real easy to see on the otto's. I feed my fish about an hour before the lights go out,and it's just kind of a pain in the neck to come back later and feed our cleanup crew. But we gotta do what we gotta do. Hang in there, we'll figure it out.