If you go by the rule of 1 inch per gallon, I consider you to be closely stocked to the limit. Maybe a few babies like 4-5 more, but no more. I wouldn't add guppies because there really isn't to much more room especially if you are gonn have babies. Just be sure that you are overfiltering and then you don't have to worry about overstocking to much. Just be sure that everyone has their own space to hide in.