SWG and stain treatment

[seilsel]

Hello, all of you inexplicably friendly folks.

I work in a pool store and had a gentleman come in at closing time tonight. He started a stain removal treatment on Friday afternoon. I didn't sell him the chems (his pool store was closed) but he is sure that the stain removal product was 100% ascorbic acid. Not sure what the active ingredient in the sequestering agent is.

Anyway, they didn't give him any instructions except to dump the acid in, followed immediately (as in 60 seconds) by the sequestering agent. He used all 4 lbs of acid in a 30k pool (doh!). The stains came up - but today his water clouded severely and his cell started flashing CHECK SALT and stopped producing chlorine. His cell reads 2600ppm, my meter at work read 3500ppm. The meter is calibrated correctly.

FC 0
TC 0
PH 7.8
TA 140
CH 80
CYA 30
salt 3500ppm

I instructed him to lower his PH to 7.2 and told him how much muriatic acid to use. He is bringing the cell in tomorrow morning at opening time so that I can test it for him.

Is there an issue with SWG's and the ascorbic acid treatment that is causing his cell to think he is low on salt?
If there *is* something wrong with the cell and it needs to be replaced, should he start introducing chlorine with dichlor or tablets? (his cya is a little low anyway - I can't really tell the guy to use bleach, but I will if either of the others will cause an issue)

Thanks if you take the time! And yes, I know that his water needs some tweaking, but I can give him that advice after the current issue is resolved.

(PS: Don't hate me, hate the system!)

 

[JasonLion]

Cloudy water is fairly normal after an ascorbic acid treatment. That should clear up, assuming he doesn't get algae.

One of the dangers of keeping the cell running is that the stains can re-deposit on the SWG cell. There is rather high PH inside the cell when it is on.

He needs chlorine, and CYA, and lower PH, so dichlor is a fairly good fit. The PH needs to be monitored. If it was already lowered before adding dichlor it could end up too low. It also looks like he needs way more CYA than even dichlor is likely to provide.

 

[seilsel]

JasonLion -

I had him lower the PH to prevent the stains from re-appearing, as described in a post here on the forums about the AA treatment. Was this a mistake?

Likely there is plenty of acid left in the water, so what do you think is a good strategy for introducing chlorine via dichlor? 5ppm worth at a time and retesting until it holds?

 

[JasonLion]

You don't want to add more than the minimum FC for their CYA level from the Chlorine CYA Chart at any one time.

 

[seilsel]

As always, thank you.

I know that helping pool stealers is not what the site was intended for. I intend to become a supporter in a couple of weeks - the info here and the help of you nice people has easily made my life $30 less difficult! And if its any consolation, I feel confident that I've saved pool owners thousands of dollars and plenty of headaches as a direct result of spending 3 hours a day reading here.

Luck in all of your endeavors.