I thought about doing that but decided I'd rather have a dedicated bottom feeder tank. It's also really easy to make sure that the bottom feeders get fed properly because they aren't competing with the fast swimming fish, and I wanted to see if I could get eggs that wouldn't be eaten by a schooling fish.
There are 4 loaches, which do swim around in all areas of the water though. I would like to make the group up to about 7 again as that will bring them out a bit more, but I worry I'll have too many fish in there.