Spot treatment and steps with citric acid - advice, caveats?

[Swampwoman]

Greetings. I am slowly learning to post first, then attempt treatment route, which is a breakthrough

Being a new bbb'er with a now lovely foreclosed pool, I am debating the best way to address 3 historic rust stains on the bottom of the shallow end, plus the steps (vinyl liner, have heater).

I wish to avoid full ascorbic acid treatment if possible since we're now in season, no iron showing up in tests, am filtering fill well water when I add, and water is nicely balanced (FC 5.5, no cc, ph 7.4, TA! 80, CAL 160) and sparkly. Have previously sequestered.

My questions:

1. If I use citric acid (which I have) in a sock set on stains and steps, will I have to mess with the pool chemistry much? Or is this viable approach for keeping pool "open" -- eg might it work even if I don't drop FC but just add a bit of acid to go down to 7.2? And could I just follow with a maintenance does of jack's magic pink stuff?

2. If I instead use jack's magic step stuff, will I have the equivalent mucking about as an AA treatment? Or is it formulated to include sequestrate? Has anyone had problems quickly bring FC back up with it?

I can live with these spots and nail them, so to speak, before closing if need be. But I am tempted to clean up the steps. I'd love to hear from anyone who's had experience with a "spot treating" approach whereby the pool remains swimmable

Thanks in advance and cheers!

 

[Swampwoman]

Re: Spot treatment and steps with citric acid - advice, cave

Ps - is there a recommended "best" iron test kit? I did not mention that the stains appear to be iron, which is consistent with my well water

 

[JasonLion]

Re: Spot treatment and steps with citric acid - advice, cave

Lower the PH to around 7.2 and keep FC near the low end of the normal range. Have sequestrant in the water before hand.

Taylor makes several good iron tests. Which one is best depends on how much iron you think you have, as the low range test doesn't go all that high and the wide range test isn't very precise at the low end of the range.

 

[Swampwoman]

Re: Spot treatment and steps with citric acid - advice, cave

Thanks, Jason, I will give that a whirl!

 

[Swampwoman]

Re: Spot treatment and steps with citric acid - advice, cave

Update for anyone who comes across this thread re spot treatment for historic stains:
I ended up using 4 8oz containers of citric acid from supermarket. It removed fresher iron color of steps and lightened heavier stains. In my mind, I thought because I was using so little I would be able to maintain my FC afterwards.
Not true -- citric acid is winning -- dropping frequently to zero but now, 2 days later, starting to hold a little. No ccs and no other signs of anything eating the chlorine but if you try the treatment yourself with spot approach you might as well do full treatment so be sure to add polyquat first as a safety measue (I didnt, but now am headed out to get some, because I cannot predict consumption rate and does the pool manually.)

That said, citric acid did a nice job of cleaning up "regular" discoloration, and maybe my reduced treatment plan will mean I get things stable again quickly. The deep, historic spots on liner may require some other plan.

My plan b is to live with the historic stains until prior to close and then vigorously treat.
Cheers.