I Agree with hugoale. Maybe put the 2 smaller ones in the larger tank and get them some tank mates as well(maybe 7-8 more i guess 20 gal per rbp). Would seem like a waste for him to be all his lonesome in a tank that large although he could end up like that monster piraya...hugoale1;4196555; said:put them all together with a transparent separater for knows the behaviour of the solitary pygo, if you see attacks trough the separater, better get another tank for the other two pygos, i got the same problem, i have 2 pygos 3" each and one 8"long, the longer pygo has lived for 3 years alone, i wait to grow the small ones and the moment to put them all together.