Spinning newt?

[erin]

I have two California newts that I've kept together in an aquarium for about a year. One of them has started corkscrewing around underwater and seeming stressed out in general. Also, he has lost weight compared to his buddy even though I feed them both at the same time (I think maybe spitting out his food). I've noticed a few other posts with similar weird corkscrewing behavior in other species, does anyone have any advice?! I don't think its the water because the other guy seems just fine.