i think my betta is sick

Question
I bought 2 male betta from a dollar store a few days ago. One came in a small cup and the other in a small tank. I put the one in a cup in a large vase and he's doing great. The other I left in the small tank. I changed some of the water and added a small plastic water tank plant. He won't eat. I've tried 2 different types of pellets and he just ignores them. He is sluggish and likes to just sit in corners of his tank. His color is fine, his eyes don't seem to be bulging and his tummy doesn't look bloated. I'm not sure what the problem is but the three days I've had him he hasn't eaten. If he's sick I'd like to know how I might fix it. Thanks.

Answer
Lisa,

I had no idea you could buy fish in a dollar store. The one in the vase is not doing great because they cannot live in a vase. He is a tropical fish needs a heater set at 82 degrees at all times. I can also imagine the other Betta's home is also not acceptable. Most likely too small. If the tank is a five gallon, then he will be good with you just adding the heater. BUT, BOTH need their own 5 gallon tank with heater no filter. Please, give them both the homes they deserve with all the fine home furnishings. As for not eating, and sluggishness, this is also due to wrong tank and no heater. Once they are put in the right tank and have all the things they need you will see a huge improvement. Betta's can go for 2 weeks without eating but the longer he goes the sicker he will get.