Stains returning

[JonnyG]

Marie -

Thank you for your quick reply. I will keep you informed on my progress and how well this method works with plaster pools. Hopefully all will go well

regards
John

[Roddapool]

Between waiting for the CL to go down and all the rain we’ve been having I finally had a chance to add chem. to remove stains and the pool has never looked so good in the two years we’ve owned the pool, and this is the first year I’ve taken care of it myself.

Here are my numbers now
CL - 0
PH – 7.2
TA – 0
CH – 70
CYA – 100

I know I have to add bleach slowly what about my TA

[mbar]

You will have to raise your alkalinity. Ascorbic acid, or some stain removers are very acidic and can bring your ph and alkalinity down. You will need to add baking soda to take your alkalinity up to 80 - 125. Since you were dealing with stains, I would keep the alkalinity on the low side - about 80. Your ph is good for now, because you will need to start to add the chlorine. Just add it slowly.

With a 25,000 gal pool, you will need 28 lbs of baking soda to take you to 80 alk. I would put in 14 lbs, wait about 2 hours, check and then add more till you get to 80. Bring up your chlorine to 8ppms right away. With a cya of 100, you need a minimum of 8ppms of chlorine in your pool. You can take it up higher if you have any combined chlorine, but you would want to do it slowly so you can watch for some stains reappearing. If stains start to reappear, then you need to make sure your ph is no higher than 7.2, and add more sequesterer.

Feel free to ask any other questions you may have