I started with 3 for a 75g 10 months ago to cycle my QT
wile the rock was curing in the main. One died in QT
and another died 4 months into the main after a velvet outbreak. Got another and he lived in QT
for 3 weeks with two farm raised percs. He thought he was a clown for a while I think.
When the 3 got added to the main, it was soooo cute when the single chromis in the main realized there was another all of a sudden. He actually flew out from behind the rocks and swam around almost wagging his tail at the new, larger b/g chromis.
The new one still hangs out with the clowns from time to time, but swims with her little buddy all the time. So, I got a school of two working fine. Wanting to add a third but wondering whether it'd be OK. 5 would be too many for me with my current stock.