ok ppl i know what silicone is safe for aquariums and am woundring is that all ppl are using to tile there tanks with is to silicone the tile to the tank then use silicone to fill the gaps like grout?? im wanting to tile the back side of the tank as im having troubles getting the crapy old paint of the outside back of tank so thought ill tile the backside of the tank like some ppl have done to their bottoms of tanks!!! thanks everyone