I have an Evo 13.5, so small. A little algae is just starting to appear and a light diatom outbreak is mostly over. Unfortunately, I see a circle of red cyanobacteria (I think) around one of my frags. I don't have fish yet. I don't want to starve the snails to death, so should I get something like 1 or 2 snails for now? Thanks in advance!