Change in Bettas Behavior

Question
Hi Lynda. We have had our betta for about 6 months. He's in a 1 gallon bowl by himself, no filtration. He is usually extremely social-whenever we walk by his bowl he comes over to "say hi." He usually hangs out at the top of his bowl or in his fake grass at the top of the bowl. 3 or 4 days ago-all of a sudden-he has started hiding ALL THE TIME. When we walk by him he darts to hide. I always find him at the bottom of his bowl now. I have been able to take a good look at him and I don't see any visable signs of sickness-no ick, no fin rot, he still eats regularly-he LOOKS completely normal but from his behavior I know that something is definitely wrong with him. I have tried a water change and that didn't help either. Any suggestions or help is GREATLY appreciated.

Answer
Hi Heather,
It could be a number of things.  If your Betta got afraid by someone tapping on his bowl, or something strange happened, he would hide at the bottom.  It could be swim bladder disease.  It could be that he is getting old. It could be that his water is too cold.  A betta must live in 75 - 82 degree water.  Below 75, he is miserable, so check the temperature of the water, and try to keep him in a warm place.  The fact that he is eating well, is a good sign.  Usually a Betta who eats, isn't sick.  I would wait a little while before giving him medication.  Meanwhile, keep his water very clean, and add 1/2 teaspoon of aquarium salt to his water.  Delute the salt before putting it in.
Hope he feels better soon, if you see any changes let me know.
Lynda