I love how they school together also no aggression. When the lights are out they spread over the whole tank. Temp is high seventies, not above 80. Food is freshwater fish. I own a restaurant so I get cases of fish at a time. So far they have eaten tilapia, catfish and baramundi. I read seafood is a no no so I stick with freshwater food. I feed fish every other day a few massivore pellets on off days. 50% water change once a month has worked so far. Tank was set up for stingrays so turnover is almost 10 times an hour very high flow. 75 gallon sump. Never test PH?
I rotate tilapia, catfish, shrimp, silversides, krill and occasional beef heart. Feed mine once in the afternoon daily as they are only about 5 months old. Will probably switch to every other day when their growth slows down. I am jealous that you can get away with a wc once a month. Keep my tank at about 77. I hope to have the same luck as you with my shoal. Thanks for sharing.