I had 2 mothers comfortably under a 250. You could likely get 4 mom's going - as long as you are taking clones every few weeks you shouldn't run into a space issue. If you want to use HPS for mothers.. it actually works well. BUT, you should think about getting a few fluorescent tubes for your cuttings instead of cramming them under the 250 too..as they don't require the light intensity as growing plants.