I don't know what to do..

[hannah16]

Alright well, Mango is slipping away right now. I don't know what the heck to do, his face is going pale and he isn't swimming just like before. I don't think he's going to last the night.. His tank is warm and I've given him a 100% water change earlier today... I don't know.. What to do for him..

[hannah16]

Housing
What size is your tank? 2.5g
What temperature is your tank? 74-80
Does your tank have a filter? No
Does your tank have an air stone or other type of aeration? No
Is your tank heated? Yes
What tank mates does your betta fish live with? None

Food
What type of food do you feed your betta fish? Pellets
How often do you feed your betta fish? 1-2 times a day

Maintenance
How often do you perform a water change? Every Other Day
What percentage of the water do you change when you perform a water change? 100%
What type of additives do you add to the water when you perform a water change? Water Conditioner

Water Parameters:
Have you tested your water? If so, what are the following parameters? No

Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed? At the store he was VERY vibrent and flareing, since I placed him into his 2.5g, he's been acting very solitary and withdrawn.
How has your betta fish's behavior changed? He hasn't really acted any diffrent since what he's doing now.
When did you start noticing the symptoms? The day I placed him into his tank, I thougt he was just adjusting..
Have you started treating your fish? If so, how? No, I don't know whats wrong..
Does your fish have any history of being ill? Not that I know of, I just baught him on the 20th..
How old is your fish (approximately)? I want to say about 3-5 months.. Not too old..