You can easily keep 20 sub adults.......adults i would do around 9-12
Overstocking without decour to establish territories helps with piranhas .....people might disagree but ive had success multiple times by overstocking pygo tanks
+1
It would probably take about 5 years to get to full adult length so he has plenty of time. 6 inches in the first year, then ~1 inch every year after that. Great advice!^^^
