I recently added about 85 pounds of coarse solar salt to my pool to kick off the season. Now there are tan streaks leading from the shallow end, where I poured in most of the salt, toward the drain. The water and white plaster surface otherwise look great, but I don't know where these tan streaks came from or how to get rid of them. Scrubbing with a brush doesn't seem to affect them. As far as I could tell, the salt was completely clean before I dumped it in. The water chemistry is well-balanced.
Has anyone seen this before or know how to get rid of it?