Stocking a 25 gal

[ponokareefer]

The blue legs hermit crabs will stay small, but if they get hungry enough, will eat snails. They are pretty cool to look at though. I would avoid the scarlett hermits. I have a couple in my 125 gallon tank, and they can be a pain, falling into LPS and damaging them, and killing snails and blue leg hermit crabs.
I would add various snails and shrimp instead. The shrimp I would hold off for a little while, but you could add a few snails right now. Make sure you acclimate them slowly, as others have posted. You could look at a brittle starfish as well after you've had your tank up and running for a little while. They are really neat as well. Just avoid the green ones, as they are fish killers.