Will using Epsom salts in bath water harm the surface of fiberglass bathtubs?
By JC from Davenport, IA
By kathleen williams  03/30/2010
I also found that if you sprinkle a little Epsom salts to my bathwater to prevent soap scum. The soap seems to float on the top of the water rather than becoming a scummy ring, then goes down the drain. I found this out after using the salts to help sore muscles. It seems that ever so little of the salts in the water helps prevent the scum. Good luck.