My Betta Darwin has been sick for over a month now. I have had him for almost two years, and was purchased at a pet store. I do a complete water change every 4-5 days, he lives in a 1 gallon fish bowl, and I use the appropriate amount of water conditioner. I feed him less than a pinch of freeze dried blood worms every day. I live in a high rise apartment building, and I am afraid the water is too cold, as I do not use a heater.
Lately, he has become discoloured (brownish/ slightly green on the head), his fins appear shriveled, he lays on the bottom all the time, and barely moves. He does not eat anything that I can see lately.
There are some pictures below,
anything you can tell me about what might be wrong with him, and what I should do would be greatly appreciated!