As long as they're cleaned out regularly to prevent ammonia build up then u won't get this issue. Tape along their height around the glass prevents them glass surfing and getting stressed out. Yes u MUST keep on top of cleaning them if u keep them in tanks, but I find it therapeutic to clean out and rearrange their decor, with 6 in one it needs doing twice weekly, if u kept less in a tank then ud need to clean it out less. But I don't find it harder to clean out, perhaps a little longer process as u can't lift it

xx