I just found out something silly. Weekly i do try to clean up the guppy tank, suck out whatever waste among the plants. Today i notice the tank's walls are quite covered with algae thick. Bey tahan, so I start to scratch it off with a plastic spoon. Then I realise as i scratch (quite tough i realise), the guppies are crowding around me busy munching the algae i scrap off. Wah lau, can't they have helped me peck off from the wall instead...
So I just scrap and they eat, didn't care to take out the algae. The guppies seem happy snacking on them.
Its nothing harmful for the fishes to eat them. Right???