White film on walls and swimmers

[StaceyI]

First let me say thank you for helping me get my pool clean and swim-able again last week! I wish I'd found this site years ago - I would've saved so much money and pool downtime. And let me properly introduce myself.... I'm Stacey, living in Northern Virginia,
with my husband and 4 children ages 16-23.

Now that my numbers are in order (see below), I want to address this weird white film on the pool walls that gets on swimmers if they touch it. Last night we had a pool full of swimmers commenting on it and the resulting "pokey" feeling it leaves on the skin. It only happens when a swimmer touches the pool wall and only on the skin that touches the wall. The film is easily rubbed off but will stay on the skin after getting out of the water if not rubbed off. The resulting "sensitive" rash lasts for about 12 hours, especially irritated when touched or rubbed. We had this same problem last year.

The pool was originally built probably 30 years ago. We have been in this house for 15 years. We had the pool walls painted white 5 years ago. There is peeling and pocking and the pool needs a re-do, but please not this season. BTW while the pool is blue, it remains cloudy in the deep end.

My questions are
Can the white film be addressed as a chemistry balancing problem?
If it is the plaster/paint can it be managed until the end of swim season, end of September?
How can this problem be avoided in the future?
Is it safe to swim?

FC 3 (in the morning; I added bleach to get it up to 7)
CC 0
PH 7.4
TA 100
CH 190
CYA 35

 

[Donldson]

Hi Stacey. That is a strange problem, I can't really comment on the film, but I hope someone here can give you an idea to that because it certainly sounds like a problem!

I do see one problem I can advise you on though: You never finished SLAMing. Your CC may be zero and you may have passed the OCLT (did you?) but your pool water is not clear so you shouldn't have stopped. If your problem is biological (again I do not know if it is) then SLAMing until you reach all 3 criteria should kill it.

 

[Bama Rambler]

My guess would be chalking of the paint. Ever got paint chalk on your finger? I bet that's what it is. If so there's not much chemically you can do about it. 5 years is a long time for a paint job to last in a pool. You could go around with a sponge once in a while and clean it off, but that's a huge job. You could also get a robot that scrubs the walls and floor and see if it'll keep it down. Of course manually brushing might help too.

 

[kcindc]

Hi Stacy,

I too live in NOVA (Fairfax) and purchased a house with a plaster pool that was painted many, many years ago. My surface looks terrible, but it is mostly cosmetic and I plan to resurface it in a few years. I keep my pool balanced, but the paint still is chaulky to the touch. I never brush the morning guest come over because of the amount of paint chaulk released into the water. I try to brush the night before a party.

Can you enter your info into the pool calculator and tell us your CSI?

If I am correct, you may want to increase your CH level to help slow the paint chaulking, but the pool calculator results will help determining where you need to be. Our fill water is soft, so you need to check the CH anytime you replace water. Keep a close eye on your PH because high PH will only make the chaulking worse.

 

[zea3]

Even thought the surface is painted you still have plaster walls and need to keep the calcium level between 250-350ppm. The chaulking may be from oxidation of the paint on the walls, or it could be related to the low calcium level in your water.