I'm new here and actually am seeking information to help my two year old's Betta fish. I have had it for several months now and for the last couple weeks he seems to be getting progressively worse and I am not sure what to do. I think I may not be properly taking care of him, I am doing what they told me at the pet store, but I have a feeling they gave me bad information. First, let me tell you what's wrong and then I'll tell you how we've been taking care of him up till now. He hasn't been eating for about a week. He has been lethargic and the first thing I noticed besides that is that it looks like something is wrong with it's mounth like it is deformed or like something took a bite out of it. So, I thought, in my naivity, he hurt his mouth, he can't eat, now what do I do. Now, his fins look like they are dissolving and one has gotten redder than before. In the limited research I've done this afternoon, it sounds like fin rot, but I didn't see anything about it affecting his mouth, so I am not sure if that's what is going on. My nephew suggested maybe I over chlorinated him, I don't know. So, he is in a 3 gallon tank, no filter. They told me at the store not to get a filter becasue it stresses Bettas, so I didn't. There is no heater, again, they didn't tell me I needed one. We have been changing his water about once a week, but we have been doing a complete water change, again, as the store told me to do. He was eating Betta pellets. The water conditioner we got last had a mistake in the measuring cup and we think we have been putting too much in and then we didn't let it sit long enough before adding the fish back. We were netting him, putting him in a small bowl, cleaning the tank and putting him back.
So, I guess first, is there anything I can do to save him, any medications, where do I get them. And, second, should we be taking care of him differently. I'm sorry I'm so clueless, but I really want to save him if I can. Can anyone give me some advice?