My betta hasn't been eating and he sometimes is lying on the gravel. Iv had him for 6 months in a 5 gallon tank by him self. The water was 85 digress F. so is the water too hot? I clean the tank every 2/3 weeks. His fins also look like he is turning into a crowntail when he is a delta tail betta. His color is less bright too. So is he alright?