Our catfish changes color!

[Sasquatch]

We're not sure what to make of it, but it's probably symptomatic of something.

Basically what happens is that at one moment our bumblebee catfish looks fine and the next time we see him, he's all pale. Sometimes it's only his head, but sometimes it's his whole body.

I think it's related to water quality, since our pH is on the high side (as high as 8.2), not ideal for a catfish.

My girlfriend think's that the food may have gone bad. Namely the beef heart and silversides we sometimes feed him.

It might also have to do with him being a fat pig and he's so bloated it streches out the color. We don't know where he find the food, but even when we don't feed him, he doesn't get smaller!

We've done water changes and stopped feeding him for a day and he goes back to normal.

Any ideas what the cause might be, and wether or not it's dangerous?

Thanks.

[cocoa_pleco]

if its right after you turn on the lights, its natural. my black shark does that since its a shock and he turns gray. If its not after the lights, something in the water is bad.