Thanks for your reply. It is Tetra, but it says Water Conditioner. Wow, I will have to reread that because maybe it was for 10 gallons, not one. I can't believe I would do something that dumb! I will definitely look into this and make it right from now on if that is the case.
Yes, I saved the jugs I bought today and I will fill at home (using filtered water) and then the water conditioner.
Well, I went out and got him a new tank - 3 gallon with a heater, cover, LCD light, and low flow filter with guard (so hopefully, he won't get caught in it). I also got a thermometer, so I checked the temperature of his little tank and it was 74 - low, but would probably been lower if I didn't leave the heater on (it was nice and toasty in the room ;). I didn't add any rocks, but I did give him his silk plant so he would have something that felt homey. It's nice to know the filter will also keep the water cleaner and the heater will keep it around 78-80.
He acclimated pretty easily and seemed to really enjoy exploring his new boundaries. His fins really sprung back too - he has new found "elbow room" and I think he really likes it.
My only concern is that he still didn't really eat. I think his sight seemed better, but I'm still not sure if he sees me or the food. I tapped the tank and he got excited like he used to, so maybe once his tank stabilizes, he'll get his appetite back.
Anyway, I would like to thank you, and all of the other posters for the help you've given me. I really appreciated it and feel more confident that I can save him. Thanks so much!