The only reason they are in the 50gl right now is I had to do some shuffling. I'm in the midst of relocating - they were in my 200gl tank with some others but I needed that tank for my Aro. They have actually put on some size since they've been in the 50, and they seem pretty happy, so I'm not worried about the minor crowding. As I said I'd like to have a 125 or maybe even bigger in my living room in the new place with my small fish in it, so these guys plus maybe 10 more loaches. The BS will need to go in with my larger fish eventually but right now he's way too small to go in my 600.