Hello, I bought a crown tailed betta a little over a week ago. I have him in a 1 gallon tank with a filter. When I first got him, he was very lively. I changed about 25% of his water on thursday (a week after I got him) so I could add more conditoner in (the bottle says to condition for the first two weeks). I put him in a separate container with his own water and also cleaned his rocks and moss ball. I feed him twice a day about 3-4 little betta pellets. Today when I fed him, he ate one pellet and then swam to the bottom of the tank. He's been staying in that area quite a while now, ocassionally coming up to the surface. He keeps puffing his cheeks out and I think he is having trouble breathing? He also doesn't seem bloated but I'm not sure. I'm scared because this is the first fish I have ever owned and I don't want to see him die. He doesn't look like he has spots or anything (I looked at pictures of common diseases that occur with betta fish). Do you think he may be constipated from overfeeding? I was going to try to give him a pea and see if that helps. My next step would be to test his ph levels, and then maybe getting him some betta revive in case he is sick. Any advice? Thanks so much in advance.