^There he is. I apologize for the bad quality, but I don't have a decent camera on anything I own. To answer those questions:

1. He is kept in a 20 gallon long tank
2. I'm using a carbon filter
3. I typically do a 25% water change once a week, but I did a larger water change a week or two ago.
4. I'm not exactly sure what constistutes as a water conditioner, but I use API Stress Coat+ every time a water change is done.
5. When I got him, he was eating fish flakes (which is what he was being fed at the pet store), but I bought some frog pellets from xenopus express several months ago, which he quickly switched over to eating.
6. I don't have a thermometer in the tank, and the water heater doesn't have a way to tell what the temperature is set to, but I would assume it is low to mid 70s.
7. No, I don't have a water testing kit.

I do have two spare tanks, a 10 gallon and a 1 gallon. I set up the 10 gallon a few days ago to move some baby plecos into it (they were in the 1 gallon tank originally). I'd gladly move him to the 10 gallon, but i don't have a heater or filter to go to it. The closest pet store is about a 40-45 minute drive, but I am considering driving up there Thursday to stock up on supplies like the things you all mentioned. And yeah, he is the only ACF I got.