Rizzil

Yup pretty sure they use lamothe by what you describe. My salt cell is IC20, I have not tried liquid chlorine yet, neither at open, was powder shock then added stabilizer in sock. For the stain removal its only been a liquid one that targets metal. I have the cell still running at 100% and will test water at pool store again tomorrow.

Ok here's my updated numbers, starting to think salt cell is dead, also now that water clearer, this ring stains look almost golden, brown, yellow. What was done to get these numbers was PH reducer, then powder shock then stabilizer, and salt cell running at 100% for 48hrs. FC 0.26 TC 0.56 CC 0.3 PH 7.4 Hardness 221 Alkalinity 96 CYA 50 Copper 0.2 Iron 0.2 Salt 3246 I will need a gopro to get you guys pics of stains.

many thanks both of you, the pool is fiberglass and brown and ring shaped, so your saying could be cobalt and very hard to remove? (we dont use well water just city water) Going forward will order the testing kit and keep water stabilized. Hopefully once water stabilized for a couple weeks can tackle the stains, will also get a picture to upload for you.

Hey Spaguy, just got the test results from the Pool store, also Vitamin C does not work on these stains, tried multiple time rubbing the vitamin onto the stain, it doesn't even lighten up. (also tried Chlorine Puck over stain nothing, and even these pouches they sell at pool store for stains and no result) Free Chlorine 0.33 Total Chlorine 2.06 Combined Chlorine 1.73 PH 8.1 Hardness 202 Alkalinity 121 Cyanuric 8 Copper 0.2 Iron 0.1 Also pool heater is on alot, wife like water hot, so must be metal staining, these stains are all from last year when I wasn't using a metal sequestor every 2 weeks. (since then no new stains)

Waterbear, i had same issue as above however vitamin C did not remove the stains. In fact nothing from pool store removes the stains. Ive been using metal sequester weekly and that has prevented new stains. But they look like rust rings however vitamin c does not remove them. Any suggestions?