I purchased a betta this morning and he seemed fine at first but he is now acting strange...he will "rest" on my plants or just simply lay on the bottom..every now and then it's like he gets a burst of energy and he will swim to the top or swim mid tank for a bit, but then he lays back down or acts lethargic. What could be wrong with him? The tank is a 10 gallon,filtered,heated,planted with a gravel and sand substrate, The water parameters are fine...he has a few tank mates that include neon tetras,ghost shrimp and a clown pleco. All of which are doing fine and pay no attention to the betta. Could it be that I brought home a sick betta? maybe he is just getting accustomed to his new home? I have another 10 gallon set up with a betta and a few cory cats...that betta never acted "odd" when I first got him.