Honestly a 7" would probably be OK but most people don't have 7"+ Loaches. Quite a few years ago I had 4 small loaches with 3 small pbass and the pbass got big so much faster than the loaches that one day the pbass had big bellies and no more loaches, I was also pellet trianing at the time so that probably pushed them over the edge. My point is the growth rate difference makes it prohibitive.