I have 4 pbass at 5 inches and a silver Aro at 8 inches. I put the Aro in the 250 g. with the 4 pbass, next day the aro had damage to one of his scales that looked bad. Day 2, the aro had what looked like a bite at the top of his head. Day 3. The aro had frayed fins and his tale was covered in a white substance and would not eat. Day 3 1/3 Aro was taken out of tank and put in another by himself. I thought that combo would work but in my case it was disasterous.