They worked!!! & they worked fast! Thank you so much Kali for the info. It's been a week since I added them to my tank & I am straining my eyes trying to see any bugs in there. I can't see anything. I wasn't sure if they would take care of the springtails or not, but as of now I can't see them anymore. I even disturbed the EE to get them jumping and I don't see a sign of them. The little gnats are history too & it just feels great to know that there are no microscopic ickys that can hurt my crabs in the tank. The hypos are all but invisible too, I am hoping they stick around for a long time. Worth every penny.. I only wish they could be bought in a smaller quantity as I still have more than half a tube of carrier left.