redearslider.com

(I looked around for an answer, and couldn't really find anything. If there's a post on this already, please direct me there. Thanks!)

I have had my red ear slider, Cheeseburger, since May. He currently resides in a 10 gal aquarium (this will be changing soon to a much bigger aquarium as well as the gravel!!) for now. He has a basking area, sun and heat lamps, and a medium sized reptofilter. I just moved around the lights from their usual spots because of algae growing in the tank and yesterday I noticed Cheeseburger breathing funny under water. His tank is cleaned regularly but his filter does need to be changed now. I'm not sure if any of this is a factor, or if this is even an issue, but I thought I would check anyways. Here's a 30 sec. clip of Cheeseburger under water.

http://www.youtube.com/watch?v=2A4YzXraVGs

Looks normal to me, but lets wait and see what others have to say...
Super cute little guy by the way, you have a water heater on the tank?

You mean the part with his mouth moving? It looks like there was a recent water change, so I might attribute it to that. That gravel should also be removed ASAP...

Very cute turtle. Mine do this all the time. Seems pretty normal to me. I believe its their way of "smelling" underwater.