What is a good amount of neon tetras in 10 gallon tank? Also, I know that these are schooling fish, but will they always stay close or do they take up all of the tank?
if theyre the only fish in there, i'd go with 10-15. They stop schooling after they get used to the tank, and only scaring them will make them school again.
It's downright difficult to do well. But if you search on the web in the last few years there was a big research project done by a university in florida on how to get them to spawn more readily and produce better offspring.
I've got 6 in my 10 gallon along with 2 albino corys, a dwarf puffer, and a South American bumblebee catfish. As others said, you could squeeze a few more in with fewer other fish.