Does it matter if I start my freshwater fish tank with sand instead of gravel? I know most use gravel, but I think sand looks more natural. Has anyone done this? I know you need to wash gravel before you put it in a tank, but do you need to wash sand? I guess I could do it by mixing it with water and then using a very fine strainer to get rid of the water... Has anyone else put sand in their freshwater fish tank?