My brother's betta Neo has been getting progressively worse in the past 2 weeks. At first, he was very lethargic, and now he doesn't even come to the top to breathe. He won't eat anything. I don't think he's ate in a week. I've used Jungle Parasite Cure and it doesn't seem to have had any effect on him. He was in a gallon bowl and the water was rather cold. My mom sent me to the store last night to buy a heater and a 2.5 gallon tank. I have also put a filter in the tank. Neo sort of looks like he's pine coning but I can't say he is for a fact. I'm really worried about him. He lays on his side and when he tries to come to the top for air, he struggles and then falls back to the bottom.

Help?

It's not fin rot. I know that for a fact.