Housing
What size is your tank?
Was in 10 gallon spawning tank
What temperature is your tank? 80 degrees
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? Was in spawning tank with female.
Food
What type of food do you feed your betta fish? Pellets
How often do you feed your betta fish? three pellets twice daily
Maintenance
How often do you perform a water change? New water in spawning tank
What percentage of the water do you change when you perform a water change? N/A
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?
Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:
Symptoms and Treatment
How has your betta fish's appearance changed? 4 hours
How has your betta fish's behavior changed? Clamped fins, low activity level, different belly
When did you start noticing the symptoms? 4 hours ago
Have you started treating your fish? If so, how? Nothing yet
Does your fish have any history of being ill? No
How old is your fish (approximately)? 6-9 months
His belly is odd. It looks slightly larger, and like he got his belly scales rubbed off. He was flaring, dancing, and nest building in the spawning tank. And, as if things weren't already bad, when I moved him out of the spawning tank my other HMPK boy jumped out on to the carpet.

Now he has raggedy fins, but still acts healthy.
Edit: And the sick boy is my 5 year old brother's. He would be really sad if he died :'(