High ph

[Mr. Muriaticacid]

Well, I opened the pool on Monday. Chlorine was 12ppm and ph as usual was off the charts using the K-1000 test kit. Today the chlorine was at 8 so I started attacking the ph. 2 gallons (really) of MA later and the ph is at 7.7. This can’t be normal nor healthy for my plaster! Every year the ph is high upon opening. A few years back we had a bad scale problem and that’s when I found TFP. Per the generous advice of the resident experts I was able to get rid of the scale by keeping the CSI slightly negative. It took a couple of seasons but the scale is gone. Unfortunately the plaster is in poor shape. It is pitted and rough and it needs a new plaster job but I’m trying to get one more year which will make it 10 years old. What I would like to know is why the ph is so high upon opening and does the plaster have something to do with it and how would I keep the ph normal during the winter.
Today’s test readings:

FC-8
CC-0.5
Ph-7.7
TA-100
CH-550
CSI-0.09

 

[kimkats]

Does your pH stay level after you open the pool? What was your TA when you closed the pool? These should get us started with this puzzle.

Kim

 

[Mr. Muriaticacid]

Hi Kim, My TA when I closed was 70 and once I balance it it’s stays pretty good but these numbers now are not typical. Normally the ph is 7.8 TA is 60 and hardness is 550-600. I try to keep borates at 50 although now borates are 20 I should also mention water temp was 65 when I tested yesterday so when the Oklahoma summer kicks in I will need some adjustments.

 

[kimkats]

How??? How and why is your pH pushing up over the winter? I am going to do some thinking and asking around.

How old is your plaster? How does it look and feel?

Kim

 

[Mr. Muriaticacid]

The plaster is 9 years old this month and is in rough shape with pitting and roughness. It was after I noticed the scale in 2014 when the ph started being a problem. It took a lot of trial and error to find the sweet spot to where I didn’t need to add acid every day during the swim season . When I get it balanced I can go 5-6 days and hold at 7.8 on the ph. I am a little apprehensive thinking about new plaster if I am going to have the same issues but I would hope that a good quality plaster job will be a brand new start.

 

[aussieta]

can you test your fill water
ph, ta, calcium hardness

 

[Mr. Muriaticacid]

I tested my fill water at the outdoor faucet I use to top off the pool.
ph-over 8.2 I’m a using K-1000 test kit so I don’t know the true reading
TA-120
CH-100

I’m surprised at the ph but in the winter I’m not adding water I am pumping it down a few times. Anyway, all help is appreciated.

 

[mknauss]

I would suspect your water comes from a limestone aquifer. So, you will constantly be fighting rising pH not only due to the pH of the water but also the elevated TA.

Harvest rain water as much as you can. Otherwise, buy acid.

 

[Mr. Muriaticacid]

I went back over my readings for last year and I noticed the CH fluctuated between 500 and 600. The TA was pretty steady at 70. My CSI was pretty consistently between minus 0.15 to minus .01. Always to the negative side.

 

[Mr. Muriaticacid]

Harvest rain water as much as you can. Otherwise, buy acid.

That why my username is Mr. Muriatic Acid, lol!