What kind of staining going on?

[Culler]

So the stains seem to come from the path of the fill water which was just a single garden hose over a couple days. It was very faint & over the 4 months its getting worse.
I picked up a Jack's ID kit but nothing. I didnt reduce PH & FC as I should have so perhaps I need to try again. We have very hard water & live in the city but even so to me it appears to be Iron. I have recently put a 20" big blue on my auto filler but not sure if that will do anything at all. The test kit I have is garbage.
Such a nice pool & area, everything going well but this really sucks & not sure how to fix it or if its fixable.

 

[Rancho Cost-a-Lotta]

Is this a new pool with a new fill? What does the pool builder say?

 

[Culler]

Yes it's new as noted about 4 months now. Unfortunately the builder turned out to be a complete narcissist with major communication breakdown. I should avoid this man for the sake of my family if you follow me.

 

[ajw22]

Rub a plaster of Vitamin C in a sock on the area and see how it changes.

it is just a cosmetic problem. Enjoy your new pool and don’t let it annoy you.