I have little white bugs or snails??? They are about the size of a large grain of sand and are very white. They are climbing on the side of the tank. There are alot of them. :-? Does anyone know what they are and how to remove them. I just order 40 new Tropheus and do not want them the die. Should I put them in the tank. I have had the tank for a week I bought it used. Help please... :?