Here are the answers to the questions:
1. I have a triangular 1 gal. tank from Petco.
2. I use tap water dechlorinated with Wardleys Watercare Chlor out and a few drops of Stress coat.
3. I've has this set-up since I've had my fish-approx. 2 yrs.
4. My betta is a loner, having eaten his only roommates when I first got him.
5. I have a plastic plant in the tank, for about 1 year now. The live one turned to mush. I also have natural aqaurium rocks, bean-sized. I learned the hard way- 2 dead bettas, the difference between natural river rocks(for decoration ONLY) and natural aquarium rocks.
6. The temp is room temp, I don't use a thermometer. When I change the water at cleaning I check by touch, not too cold, not too hot.
7. No filter, this tank came only with an air stone, tubing and a light. Petco advise that this would be all I needed.
8. What is a CO2 unit? I'm guessing I don't have one since I don't even know what it is.
9. My aquarium receives natural daylight all day long but it's not sitting directly in the sun. But the room gets lit very well.
10. I last cleaned the aquarium 1 1/2 wks ago. I have noticed that the leaves on my plant have gunk on them already which usually doesn't occur until week 3 when I'm ready to clean it so I know somethings up.
11. I clean the aquarium about once every month, it really doesn't get dirty. Seriously. And I'm constantly looking at his water to make sure it doesn't need it sooner.
12. I feed Betta Bits and blood worms, the worms not so often. I feed once a day in the evening. I thought I was supposed to feed only once a day but after reading your site I'm seeing that I should be doing it 2x's.
13. The lighting is the one that came with the tank but I don't really use it because he starts to puff up and attack his reflection in the glass the second the light goes on. I figured he'd be less stressed and I'm in So. California so it's got natural light pretty much all day long into the evening.
14. The bulge in his side just recently developed about 2 weeks ago, but for sure before the last cleaning. It looks like an air bubble and upon closer inspection with the light on, when he was at the top of the tank I could see the light coming through it so it's definately not solid. It's on his right side, lengthwise from his fin to almost the top fin and widthwise, from the bottom of his body to just past his midline. It doesn't prevent him from swimming to the bottom or staying down there. I'm just concerned for my fish and that this will get bigger, I'm afraid it's going to burst and that wouldn't be good.
15. I didn't know I was supposed to test the water with this type of set-up, at least that's what the Petco people told me.
17. We got our fish about 2 yrs ago and like all the other bettas he didn't move much, I assume because of the cramped confines of the cup. But he got active once you picked up his cup. At home he's a regular active fish but his demeanor is a bit stressed lately. By the way, his name is Petals.