I got a new Betta Fish in April...and he was doing good for a while....now he just sits at the bottom of the tank and hardly swims around. Am I supposed to keep his filter and light on all the time? should I take out the plastic plants that came with the aquarium? Right now I feed him... BettaMin tropical Medley. I cant tell if he eats enough or to little, because the filter eats it up after a few minutes. I really don't want him to die.....so if anyone can help!!!!! Please!