Ok so I have a Blue food grade 55 gallon barrel to store my salt water in. I have a power head to keep water moving and a heater to keep it to temp. There seems to be a tannish white chalky film in the bottom and on the sides of the barrel and its coating the power head and heater. I showed it to my friend ( who is responsible for luring me into this hobby) and he has no idea what it is either. I have about 40 gallons of mixed water in this and would hate to lose it all. But I am afraid to use it and general consenses is it needs to be dumped. I am looking for some some direction one way or another. Would like to know what it is and how to avoid it if it is something that is going to cost me 40 gallons of salt water. Thanks in adance for the help!!!