blow on them. if they jump, they are springtails. and most people pay money for these so good deal if you got them for free other than that they might be dwarf white isopods. but they dont look like it from the picture. kind of hard to tell since they are so small.

if its neither.....i wouldnt keep my red eyes in a tank full of bugs not knowing what they are. try blowing on them and checking old poop.