Moved from Original topic Here Mod Patrick B
I have similar problem with white powder. It is a new Hayward salt chlorination system and the cell is clean. All chemicals, including calcium and phosphates, are in the normal range. I use a Porpoise paper (accordion) filter which is only a couple of months old. Last time I cleaned the filter, it was somewhat clogged with the white powder and it was caked on the bottom of the cartridge housing. The substance has no taste or odor. This is not the normal crystallization that you get with a salt cell. The folks at the local pool store seem stumped. I'd appreciate any ideas.