Insect and Spider Identification: CLOSED: Insect in Turtle tank, 1 by Timotheos

Timotheos wrote:
I was cleaning my turtle tank today and noticed a large amount of these strange insects hanging around the stones at the bottom of my tank and the surface of the water. It swims/moves by sort-of folding over itself very quickly. I've never seen anything like this and I've never had insects in my tank before. I'd love to know what it is and how it could have gotten into the tank.

In the photo, he top half is a reflection. The insects are about 5mm long