I have 5 in a ten gallon with a "cave" theme. Very low maintanance fish. I bought them because I felt sorry for them but they get along fine without eyesight and have no fear instinct because they have no natural enemies in the wild caverns of Mexico. Fun to watch swallow bugs half their size whole. takes a while but they never give up. Can feed them day or night because they have no sense of time and never seem to get tired!