Hi folks. So I'm keeping Neon Tetras for the first time in a 20g community tank with guppies/endlers, cories, and otos. Petsmart had a large school of them that were looking very healthy and on sale for 80c each. Very fitting fish for 4th of July weekend. Couldn't resist the temptation to get 6 of them. Is there anything I should keep in mind? Currently they're all clustered at the back corner of the tank hiding from view, that's normal in the first few days right?