I have four in my 62 gal tank. I got very mixed reviews on keeping them, some saying my tanks too small, numbers not high enough but on the other hand i know people to keep them in similar sized tanks and in similar numbers for 12 yrs plus and have no problems. Im not sure which is right and which is wrong and as i found, looking on the net for many hours the same results some good some bad. Im my personal expirience from the time ive had so far and with other people its a matter of how you look after them and what you house them with, including decors. Again im not saying im right but its just personal expirience. And as said above, they do take a very long time to grow.