There's something wrong with my peppered Cory... I have one cory in my 10 gallon with two balloon mollies and one guppy. The first 3 weeks that I've had this Cory, he acted normal. But starting today I think he is ill and there is something wrong with his internals.. Every hour or so I find him floating at the surface on his side, and he looks lifeless. However when I take my net and touch him with it, he suddenly "comes back to life" and swims to the bottom. Once he's at the bottom he doesn't stay still like usual. He has difficulty staying right on the bottom of the sand and he's floating just above it. He wriggles back and forth and it looks like he is having a really hard time. I feel so bad for him what should I do... And if I can't cure this, should I euthanize him?