Does anyone have any advice for removing algae from sand? I have a plec, yamato shrimp, etc etc. and they do a fantastic job of keeping the leaves and decorations clean but I now how algae forming on the sand at the bottom of the tank, I've got some really good algae killer but don't really want to be adding chemicals to the water unnecessarily + I don't wan to take away the main food source of my plec and shrimp, any advice?