It just totally depends. There are a number of genera which implies a myriad of life histories and env. needs. The hollywood stunner can be kept under intense light and will grow fast. The hobogato hot pink chalice can go up fairly high, does well for me. The rest of them I keep on the floor or a decent distance from the halides. Low - moderate flow as well. Feed at night when the feeders come out; some are very short and others are very long so placement for "safety" can be tricky too.