My betta fish was so active when I first got him. Then for the past week he had been litteraly hiding in the corner of his cave and only comes up for air! His tank is clean I even did a huge cleaning today. I don't get it. He's healthy, he swims with no probs and doesn't lie on the gravel on his side or anything. I bought captptpa leaves will that help? How much does your betta fish hide and for how long? Mine does every day I rarely see him.
Give this a shot so we can better see what's going on. Housing
What size is your tank?
What temperature is your tank?
Does your tank have a filter?
Does your tank have an air stone or other type of aeration?
Is your tank heated?
What tank mates does your betta fish live with?
What type of food do you feed your betta fish?
How often do you feed your betta fish?
How often do you perform a water change?
What percentage of the water do you change when you perform a water change?
What type of additives do you add to the water when you perform a water change?
Have you tested your water? If so, what are the following parameters?
Symptoms and Treatment
How has your betta fish's appearance changed?
How has your betta fish's behavior changed?
When did you start noticing the symptoms?
Have you started treating your fish? If so, how?
Does your fish have any history of being ill?
How old is your fish (approximately)?
I was going to suggest the same as CrazyKat. Those questions will tell us more to try to help.
My first thought was that maybe he's cold; if the tank is 76 to 82*, he'll be far more active than if it's only 70 or 72*. Heaters are a must for these tropical fish but sometimes people dont' know that.