Ich won

[Adastra]

I don't see any ich cysts either. It's possible he could have died from a secondary infection.

One thing you should understand about ich is that ich bugs very commonly exist in almost everyone's aquarium, but since it is so prevalent, most tank-bred fish like bettas have built up a resistance to them. Because of this resistance, fish only actually become infested with ich if they are under some kind of stress that weakens their immune system--such as low temperatures, temperature fluctuations, poor water quality, rapid changes in water conditions, and other stressors. You should carefully evaluate how your fish's living conditions may have contributed to his infestation. Purchasing a reliable liquid master test kit and a couple of glass in-tank thermometers is a great idea, if you haven't got them already.

Sorry for your loss, best of luck with your next fish.

[Red and Bob]

At the time when he got ich, I didn't have a heater and hadn't cleaned the tank in about a month because I didn't know that you had to clean them so often. Also, I had just added another fish to his tank, a pleco, which Im pretty sure brought the parasite to my tank because he was fine before that. I can assure you he did have white spots on him. I was treating him so some fell off, that led me to believe he was getting better. He was covered in ich to start with. I took the pleco back and even the petsmart guy seemed well educated about ich (except he didn't know that aquarium salt can kill it). He knew the pleco had ich. The pleco wasn't as covered in it was my betta was though. Actually he had large patches of something on him that wasn't quite right. Also small dots that was ich. I had my betta for almost 4 years, with no heater and didn't change his water as often as I should have and he never once got a disease. He lived for a long time. Thats what led me to believe the pleco brought it to my tank. The stress of everything could have killed him. Having to change his water everyday, treatment, the parasite, and his old age. It sucks because it really looked like he was getting better. He looked so much happier. He was swimming around instead of laying at the bottom and the ich was falling off....It just sucks he died...

[Adastra]

Yeah, ich is not a fun thing to go through. Another thing to understand is the life-cycle of the ich. The ich has to leave your fish in order to reproduce--this is the only stage of its life cycle where the medication can take effect and kill the little buggers. When it's on the fish, it's actually burrowed into the skin, and is protected from the medication--this is why your fish continued to get worse even though the ich looked like it was clearing up. :(

Hopefully now that you've had this experience you'll make much more informed decisions about your next fish. :)