I got Valentine yesterday and he acts really odd. Sometimes he’ll sit at the bottom of the tank, just kind of rest with a slight bend in his body then he’ll just start swimming again out of nowhere only to go rest again. It’s worrying. He’s in a big tank that was for my last fish, 10 gallons. He also has a filter and heater. I changed some of the water yesterday because I thought it would help. Is he sick? Or just adjusting from a tiny cup to a big tank?