I have a 20 gallon tank with 5 neon tetras and 3 ember tetras and 5 corydoras. The tetras numbers are small due to a disease that killed many of them. These are the ones that survived and have been alive for months now after the disease. I have 8 néons that are doing well in qt soon to be added. I originally had 6 otos in there too but 5 of them have died without showing signs of being unhealthy and I have a feeling the last one will too. I have had a really hard time keeping otos alive in the past and need a good algae eater for the 20 gallon because the algae never stops growing. Does anyone have any suggestions that will be compatible with the fish I already have. I plan on having between 10-15 of the two kinds of tetras as well as about 6-8 corydoras. Any suggestions as to what algae eater I could add.