catfish playing with bubbles?

[shale]

My roommate has a small freshwater tank that currently only has one fish in it, a big fat old catfish. Today I noticed that he was hanging vertically against the side of the tank, right below the filter. He's not actually playing with the bubbles, but he chilled out in that spot, as opposed to his normal place behind the fake driftwood, all day.
Is this his way of telling me that the water in the tank is nasty and he's having trouble breathing and I need to change some of the water? My roommate typically does very little maintenance on the tank. Typically she'll just top off the water when needed and add some stress coat.

I'm hatching plans to totally upgrade her little 10-gallon with a 50-gal planted tank, but those plans are still very nebulous. In the meantime, is there something I should be doing to make her catfish more comfortable? Or is this just a catfish thing?

Thanks!

[PEMfish]

We need real info. With quality tested kits give us Nh3, No3, no2, PH, and GH readings.

[shale]

well, that's part of the problem..... when I said very little maintenance I meant pretty much none. I don't have any test kits on hand for this tank. It's really a "feed daily and top off water" sort of operation.
Before the roomie and I make any real plans for the upgrade to the larger tank, we're going to have to sit down and discuss what it will take to properly maintain the thing; water quality, filtration, lighting, etc. etc.....
The catfish has hung on through other fish coming and going, temps in the tank climbing in the summer and dropping in the winter (before the house ac or the tank heater get turned on/adjusted), water levels getting low..... I have no idea when the last time the filter was checked or cleaned.
I've just spent so much time over the past year learning to watch and maintain Anselth's reef tank that I feel bad almost totally ignoring Kris's freshwater.
She, of course, is not home. It's the weekend, so she's down at the Shore. :}

[PEMfish]

Do not spend money on a new tank till you can prove to yourself you have the ability to care for it. I am not seeing that in the least now. Get some good test kits and stick to a thorough maintenance schedule.

[shale]

I'll be sure to pass your advice onto the tank's owner. Thanks!