Stains from roofing nails

[Jen_with_one_n]

Hi all!
I have rust stains from roofing nails on the floor of my plaster pool.
I began the ascorbic acid treatment this morning after bringing the FC to 0 and adding algaecide. I added 1 pound of ascorbic acid about 10 hours ago and there has been zero improvement!
Help!!

PS: My pool is 15x 30, with a tanning ledge, deepend is 6 feet. I’m not 100% sure the volume but from what I read the guidance is 1/2 to 1 pound per 10000 gallons so I figured a whole pound wouldn’t hurt and wouldn’t be too little

(Feel free to move this to the proper forum if I opened it in the wrong spot)

 

[ajw22]

Did you confirm the stains lift with some Vitamin C paste before beginning the AA treatment?

 

[1poolman1]

 

[Jen_with_one_n]

Did you confirm the stains lift with some Vitamin C paste before beginning the AA treatment?

Yes. I rubbed vitamin C tablets on one of the spots and it lightened.

 

[ajw22]

Where did you get the ascorbic acid from?

 

[ajw22]

View attachment 433124

From Ascorbic Acid Treatment - Further Reading

Another alternative is oxalic acid, but one has to be careful to not overdose or use it in high CH conditions due to the precipitation of calcium oxalate (i.e. it's OK as a local spot treatment, but not so good for a broad amount -- probably no more than 1 ounce per 10,000 gallons). Oxalic acid has a higher toxicity profile (so just be careful not to get it on your hands or inhale dust) though it's still less hazardous than some other chemicals we use for the pool.

 

[Jen_with_one_n]

Where did you get the ascorbic acid from?

PC NetwoRx Pure Ascorbic Acid (Vitamin C) Powder (1 Pound) https://a.co/aU0piKL