Actually, last night, one of the catfish finally came off the left wall. Not much, only about 2", but he kept "flashing" his belly onto the front glass. This morning and now, they're swimming around the tank -- mostly the left half of the tank, but they're getting to the middle anyway, and they've even strayed all the way to the right-hand side!

My filter was part of a kit, TopFin Model 10 Power Filter. How do I know when to change it? The box says once a month; is that still correct for a new tank?

I bought an ammonia test kit on my way home from work tonight. The ammonia level was between 1.0 and 2.0, definitely not over 2.0, so I did another 5% water change. After the water change, it's right at 1.0, so I'll do a 5-10% change tomorrow. Nitrite still reads zero (will nitrite go up as ammonia goes down?). I don't have a nitrate kit yet, but plan to get one later this week.

Thank you. I did some research before I got these because I wanted to do it correctly. The info with the kit was woefully inadequate so I relied heavily on the Internet with its often contradictory information. The kit said to cycle the tank for 3 days, which I did, ignoring Internet articles that said to cycle for a week before adding fish; I thought I'd screwed up by not cycling it longer. Should I be testing for ammonia and nitrates, or does the nitrite test tell me what I need to know?