Hiding and not coming out?

[madmonahan]

My betta Mr.Grumpy was active and healthy all DAy yesterday. At night he started hiding under his decoration, it scared me to death because I didn't know where he was! I found him and thought he was just resting, but he has been doing this all day today and is not coming out for air. He is either breathing hard, or hardly. It is worrying me very much. :(


Housing
What size is your tank? Divided ten gallon
What temperature is your tank? 78-80
Does your tank have a filter? Yes
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?
A betta on the other side of the divider, the boy on the other side is healthy and active.
Food
What type of food do you feed your betta fish? Aqueon Betta Pellets.
How often do you feed your betta fish?
2 pellets 2x a day, occasional frozen or freeze dried bloodworm.
Maintenance
How often do you perform a water change? once a week
What percentage of the water do you change when you perform a water change? 50%.
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?
N/A
Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed? Maybe a bit clamped? Can't tell because he never comes out.
How has your betta fish's behavior changed? Hiding under a decoration and not coming out for air, breathing heavily or barely breathing.
When did you start noticing the symptoms? Last night.
Have you started treating your fish? If so, how? No.
Does your fish have any history of being ill? I got him about 3 weeks ago, no other illnesses
How old is your fish (approximately)? 1 year?

[madmonahan]

He came out finally, I'm going to turn off the light and see what he does.

[callistra]

Use a drops test to test water for ammonia, nitrite and nitrate.

Cycling takes up to 2 months and takes careful monitoring of levels and ammonia and nitrite should never be allowed to get over .25ppm. 50% weekly including using a siphon to vacuum the gravel is good for a fully cycled tank but if that's all you're doing while it's trying to cycle you probably have a water quality issue.