Stain at waterline at white stairs only

[zackpool]

Opened 2 weeks ago. Everything perfect per open and close procedures! 2nd week, light chocolate stains
appeared at waterline in white stairs. no stains on the liner. Brushing, magic eraser, NOTHING I tried has touched the stains! Razor blade did nothing!
Thoughts? REMEDIES?

FC 6
CC 0
PH 7.6
TA 80
CH 200
CYA 60

 

[Texas Splash]

Even though you're on city water, dark stains after opening and increasing FC "might" be a result of iron in the water. Iron stains don't always have to hit the same location or stain the entire pool at once. Have you tried some vitamin C tabs (crushed) in a sock or nylon? Try a few on those pressed/rubbed against that stained area for a few minutes to see if you get any changes. If it does, it's iron.

 

[zackpool]

Even though you're on city water, dark stains after opening and increasing FC "might" be a result of iron in the water. Iron stains don't always have to hit the same location or stain the entire pool at once. Have you tried some vitamin C tabs (crushed) in a sock or nylon? Try a few on those pressed/rubbed against that stained area for a few minutes to see if you get any changes. If it does, it's iron.

Went to pool store for Stain Out. $50.00! read label mostly ascorbic acid.Went to Sprouts,
100% Vitamin C, Pure powder.
Took wife's nylon, cut foot off and added 4 oz. Rubbed and rubbed over same tiny spot for 5 minutes....spot did get lighter, did not go away.My arm gave out before the spot did! I got 12-15 feet that is spotted....should I add water so it rises over stains (1-1/2 inch) and add metal out and pump for 24?
Thanks!!

- - - Updated - - -

Even though you're on city water, dark stains after opening and increasing FC "might" be a result of iron in the water. Iron stains don't always have to hit the same location or stain the entire pool at once. Have you tried some vitamin C tabs (crushed) in a sock or nylon? Try a few on those pressed/rubbed against that stained area for a few minutes to see if you get any changes. If it does, it's iron.

Went to pool store for Stain Out. $50.00! read label mostly ascorbic acid.Went to Sprouts,
100% Vitamin C, Pure powder.
Took wife's nylon, but foot off and added 4 oz. Rubbed and rubbed over same tiny spot for 5 minutes....spot did get lighter, did not go away.My arm gave out before the spot did! I got 12-15 feet that is spotted....should I add water so it rises over stains (1-1/2 inch) and add metal out and pump for 24?
Thanks!!

 

[Texas Splash]

should I add water so it rises over stains (1-1/2 inch) and add metal out and pump for 24? Thanks!!

Perhaps. But I was hoping to hear of more positive changes in that staining test. One other question, other than salt for your SWG and perhaps some acid, have any other products been added to the water? Anything else from the pool store perhaps? We want to rule-out any other possibilities.

 

[zackpool]

100% pool school only. Since opening....4-121oz 8.25% bleach dated 17.....2 121oz 6% bleach...50 oz baking soda
That's it...brought alkalinity to 85ppm. Low speed pump started at 24 hours now down to 8 hrs.Wife says pool is "beautiful except stains"

 

[Texas Splash]

Great. Well, I'm always cautious and running-out to buy something before trying at-home tests. So, before you do purchase any stain-out product, perhaps try these two things as well:
- If you have any chlorine tabs, or perhaps some di-chlor in a bag, apply a little on that on the area to see if it changes. Your test numbers look good, so I doubt the stain is organic, but it wouldn't hurt to check
- An elevated pH (along with FC) can cause iron to precipitate out as well. Your numbers are not crazy high, but perhaps lower pH to about 7.2-7.4 for a day or two. See if that changes anything. Also, with an SWG, a CYA of 70 might work better for you and allow you to lower your FC just a tad. Again if it is iron, those two things may help and don't cost all that much. Fill the pool up over the waterline and give that 2-3 days or so and see if it helps.

If none of those things work for you, then sure, you can try the metal out. You might also consider a product like Jack's Magic Stain ID Kit to confirm. Just a thought.

 

[zackpool]

Excellent ideas! Will proceed
accordingly and give an update on a couple of days!
Thanks for your time and efforts!