Hi, I'm very sorry about Bob. If you only had him for two months, I would agree that he may have already been sick. Yes, it is also true that 82 degrees fahrenheit is too hot for betta fish, although they are tropical fish. I hope you got another fish. You can read in some of the article here at the Fish Site on
www.BellaOnline.com about betta care - having to do with water conditions appropriate for bettas - including water temperature, dechlorination, conditioning, and pH - including the most important thing - which is cleaning the tank often enough. They usually get diseases from lack of consistently clean water - and this is one of the main problems when you buy a fish at the pet store. Even if their water in the little cup they are in looks clean the day you see him, you'd have to come into the store frequently over a long period of time to see if their staff is really keeping the water clean and otherwise taking good care of the fish.
This is something we've talked about a lot in the past here at the fish site - the lack of care of pet stores sometimes. The fish in aquariums with water filtration systems are usually in better condition.
Then, on the other hand, there is the whole discussion of what happened to the dear betta fish before they even arrived at PetsMart or Petco or Wal-Mart or any other stores where you find them. In other words, it also depends on the living conditions in which the breeder keeps them and ships them in to the pet store.
Some people even buy the sick bettas on purpose in order to try to save them.
I'm really sorry about your fishy. I really hope you get another fish to love.
There are many great books on betta care and I've suggested some good ones in some articles here at the fish site.
There's a great one on basic betta care by Animal Planet, for example. You can find some in libraries, pet stores, and online.
Once again, my greatest sympathies for your loss.
Please bless another betta fish with your love and care. He will really appreciate it.
