hi i have a silver aro around i wanna say mayb 7-8inches and lately she has been going toward the middle and bottom of the tank since i had to take the top off my tank cuz i had the eclipse top on it and the filter was not good engouh so i took it off and put a ac110 and then put clear acyrilic on top so im guessing that might be the reason cuz now she sees the openness above but i dont know and she was swiming up on top for a few days after i did that but after i turn off the lights she is swiming on top and its a 29gallon tank i know its to small but im in the process of setting up a 210 and when i bought her she was about 4inches long and nows she has basicly doubled her size and i was just using that tank as a grow out for my pbass and aro