hi, i just bought a Rose Anemone and i fed him, and everything, but after 7 days, he died. I tested the water levels, and other things in the water, and it was all fine. he turned whiteish, and got really small, and started to fall apart, and got really slimy. I did everything the store people recommended, and it still died. what did i do wrong, or did he just die, cause of age???