I have a 20g high and had a stocking question. My tank is planted with a top fin power 20 filter ( I took out the cartridge that came with the filter, and added in as much sponge that would fit, plus a pre filter sponge ) . Right now the tank has 8 harlequin rasboras, 6 pygmy cory, 1 dwarf gourami, 2 amano shrimp. I have had a lot of algae on the glass and was thinking of getting a nerite snail, or maybe just adding another amnao shrimp. Just wondering what every one's opinion was?