My first fish, Dahli died last night. I knew his conditions weren't perfect but I already have a larger tank and a heater on the way to move him into one I could cycle it. He was in an unheated one gallon. I was feeding twice a day (with one fast day) and doing 100% changes twice a week. I know bettas need warm water which is why ordered a heater. I tried heating the one gallon but it was way too warm and I figured he'd be fine for about a month until I could get everything worked out.
He seemed fine yesterday. He was swimming around. He stressed out as usual when I cupped him to change his water, maybe a bit more so. He seemed fine when I first put him in the tank. Swimming around, maybe more than usual. I turned the light off and I could hear him splashing around a bit. I turned on my light briefly at one point and he was lying on the bottom of the tank. I figured he was just sleeping and left him alone.
This morning I woke up and he was in the same position he was the night before. This seemed odd so I tapped the glass to wake him up. He didn't so I stuck my hand in the water and tried splashing around and then tried moving the decoration that was next to him. He's dead.
There seems to be a grey film over his body that wasn't there last night. I don't know if film is the right word. Basically he looks grey but you can still see his colors underneath.
The only other living thing in his tank was a moss ball that I actually didn't put back in after the water change yesterday.
I'm eating myself up here. I'm sure it is something that I did. Everyone thinks I'm crazy but I grew very attached to Dahli in the month that I've had him. I had just decided to try and teach him to jump for his food. I loved the little bugger and he had a great personality. I want to know what it was so I can know if it really was my fault and also so I know better in the case that I get another fish (which I certainly wouldn't do until after I have the five gallon set up, heated, and cycled).
Any help on identifying the problem would be much appreciated.