How does this even work?

[Nano]

Yeah I believe one nano was maybe 25 gallons tops, had 6+ tangs a handful of clowns, 3 triggers some angels and some others I didn't know the names of, and he had 2 tanks like that then a 1x1x1 cube with a adult clown 4 chromis and 2 other larger fish I didn't know what they were either. He's a hazard to this hobby even more then me! Jk