So about a week ago I found some spots on the floor of our pool. They were rust colored so I thought I would try vitamin c. It worked but two of the vitamin c pills left some dark spots. One is about the size of a quarter and the other is the size of a fist or so. I searched the forum and found that this could be from copper. I also laid a puck on the stain for quite a while with no change.
I'm wondering why the other vitamin c pills didnt stain the pebble or if something else could be the culprit. I cant test for copper but will take a sample to Leslies and see what they come up with. I havent used anything in the pool besides pucks, acid and bleach. I put some coins by the stains for size comparison. Any help would be appreciated.