I house 1:4 or 1:5 in a 10g then once they reach that golfball size and are about to burst I transfer them to the birthing tank, which houses between 2 to 4 pregnant/nursing females at a time, nursing and weaning, once eyes open they get moved to the weaner tank. Then the moms get put back in to be bred again.

My largest litter so far is 19, and we average about 12 to 15 per litter.