Calcium Stains vinyl liner

[chemistrydropout]

Opening my pool this year I developed calcium stains on the vertical walls of the pool. I was using bleach and cal-hypo tabs to clean up and the stains showed up once I got the water clear. I have lowered the pH to 7.2 and begun to aerate to help remove the staining. Anything else that I could do to help the process? I scraped some of the stains and put them in vinegar and they fiz and dissolve. I have ceased using the calcium hypo and just using bleach after this disaster.
20 by 40 vinyl liner pool with a sand filter 1 hp Hayward pump no other features 35000 gallons
TfP 100 test results
Fc 7
Cc 0
Ta 80
Ph 7.2
Ch 110
CA 30

 

[JasonLion]

It takes a while to get calcium scaling off of vinyl. The most effective approach is to keep the PH around 7.0 to 7.2, let the TA go down, and to do as much scraping as you can manage. The low PH will slowly dissolve calcium out of the scale and back into the water., while scraping will remove calcium from the water completely.

 

[chemistrydropout]

Thanks for the guidance. Should I be concerned that the Ta is getting low/lowered. Should I bring it back up at some point in the process.

 

[JasonLion]

TA going down is part of the process of getting rid of the calcium scaling. You don't really want TA going below about 40, but other than that you shouldn't raise TA until the scale is gone.

 

[chemistrydropout]

Thanks. As my sig suggests I am a little challenged on the process and in the back of my mind I'm thinking that I need to raise the alkalinity to keep the process going. It is working. Less than 24 hours in the scale is getting easier to brush off. New liner last June so I am trying to be as gentle as possible to avoid damage. The scale is just like sandpaper or glass. Can I get a refill for my TF_100 or is it just as simple to buy a new kit? This pool opening blew thru my kit due to a lengthy slam and replacing over half of the water to lower CH.

 

[Richard320]

Thanks. As my sig suggests I am a little challenged on the process and in the back of my mind I'm thinking that I need to raise the alkalinity to keep the process going. It is working. Less than 24 hours in the scale is getting easier to brush off. New liner last June so I am trying to be as gentle as possible to avoid damage. The scale is just like sandpaper or glass. Can I get a refill for my TF_100 or is it just as simple to buy a new kit? This pool opening blew thru my kit due to a lengthy slam and replacing over half of the water to lower CH.

You can buy just the individual reagents or the whole refill package from http://tftestkits.net. If you don't own a speedstir, treat yourself to one.

Having dissolved some scale myself, I can tell you it takes a long time to get rid of it. Think glaciers. Also, the stuff you're dissolving is going back into solution, so you will see your CH rise.

 

[chemistrydropout]

It is a painstaking process. I anticipated that the calcium going back to suspension would raise CH just unsure what to expect as "target". The key is keeping pH low but not too low. My pH kit only test to 6.8 and I am concerned with going below that. I have been targeting between 6.8 and 7.2 and at the end of the day I am rising to 7.5. I think I am losing progress in the afternoons. Rain is forecasted the next couple Of Days So I Am Expecting some help from mother nature. It could make it worse. Will just have to wait and see. Several of my neighbors are experiencing the same issue.

 

[Go_Habs_Go]

Just bumping an older thread as I think I may have calcium staining on my vinyl liner. How did everything turn out for you?