mine currently eating anything they can scavenge, sink cat pellets, prawn, basa fillet, blood worms, and any fish that happen to swim in their mouth.
at the moment the algae dosn't seem to be a problem i think the plants keep it at bay. the plants growth is good in the tank i think its aided by the fact the back is painted green so light only gets in through the top.
the snakehead tank get bit from the window at one end but it only take a couple of min to remove it.