[AZGuppyGuy]

Should I be worried about one of my guppies? I'm not sure what to do.

 

[ichthyogeek]

Nah, sometimes fish do that. If it was a lot, then I'd think that maybe a water change might be necessary, but one fish out of all of them is probably "glass pacing": getting exercise in a place it knows is safe for it to exercise.

 

[Aaronious]

This tends to be something newer fish in a tank will do as well. So if it's new it should slow and stop in a week or two.