New plaster keeping the PH up. How much and how long?

[Tallredrider]

I have a new pool, Yayyy!!! It is fairly large, holding about 30,000 gallons. I have been unable to find information about how hard I am going to have to battle the PH continuously increasing. It has been 3 weeks ago today that it was filled with fresh water, and I am finding that I can get the PH down from 8 to 7.6 with a gallon of Muriatic acid (14.5%). But I am finding that my PH is right back up to where it was every 3 days. So I am going through 2-3 gallons per week. My TA is a touch high, at 120 ppm, but is obviously slowly decreasing from its peak of 140. I expect to babysit this pool and its chemistry very frequently at first, but it seems that rising PH is just a little out of hand.

The question that I have for the gurus here is if that is unusual. I do have a hot tub that has not been heated yet. The hot tub drains over a water feature and into the pool. It is set to a pretty slow trickle, and I wonder how much that could be contributing to some aearation, thus increasing PH as well.

Overall, I have gotten a pretty good handle on all of the chemistry, considering myself some sort of Walter White acolyte. I appreciate the good information here.

 

[mknauss]

Welcome to the forum!
Can you fill out your signature? pH depends on if you have new plaster and the TA of your fill water. We know the fill water TA, but do you have a plaster pool?
Do you have a proper test kit?
I suggest you read through Pool Care Basics - Trouble Free Pool and even look at a few of our videos TFP-TV - Trouble Free Pool

 

[Tallredrider]

Thanks for your response. I updated my signature, but the title of the thread states this is a new plaster pool. So I think I am fighting some of the plaster curing and have read it can take a year to become unnoticeable. But this much acid feels like a lot, just wanted confirmation that it can be normal.

The test kit I am using is the Taylor Technologies kit. I found the test strips to not be worth a darn, even after getting a second type. I just have more faith in a liquid chemistry set. I am not color blind, but when I look at some of the test strips, I feel like it.

 

[mknauss]

Have to admit I did not catch the plaster in title.
Test pH every day and add acid to lower the pH into the upper 7’s. Test TA every few days as you need it in PoolMath to determine how much acid to add.
It should slow down after the plaster dust subsides and TA is below 100. Then you likely can test every other day.

 

[Tallredrider]

Thank you Mknauss! It has been over 3 weeks since the pool was filled. We see a lot less plaster dust now, and have felt comfortable decreasing our pool brushing from twice a day to just once per day.

PH shot up again today. Just added more acid. The calculators have been awesome. Any experience from the group how long I am going to chase this? I understand that chasing PH is a way of life and continuous adjustments will always have to be made, but am hoping to reach some sense of stability eventually.

Another question: Boric acid will likely help to stabilize my PH as well. When would be the best time to make that leap?

 

[mknauss]

Your fill water TA and the amount of fill water you add due to evaporation will keep the pH rising from spring to fall. So 'stability' will be just adding acid every other day or three.
Borates you can add anytime. Do not expect a panacea. It might change adding acid every other day to every 4 or 5 days. You will still use the same amount of acid overall.

 

[PoolStored]

Any experience from the group how long I am going to chase this?

We have seen anywhere from 6-24 months. Every pool is different...

 

[MichaelT20]

Also do you have any waterfalls (spa spillway) or a Salt water generator? Swg shouldn’t be running yet if you do, but both of these will contribute to ph rise.

I’m almost exactly a year since my plaster pool got filled. My ph rises 0.1 / day on average. But I have a spa spillway running 12 hours a day and a salt water gen. Pools 21k gallons.

 

[Tallredrider]

There will be a SWG installed pretty soon. I think my pool guy says a month is good for that. Sound about right?

There is a spa spillway that is currently running all the time. I am also told I can decrease the time running after a month.

It sounds like I should be buying the muriatic acid in bulk!

Thank you all for the help.

 

[titleistseemore]

We are 7 months from our innital fill, still adding acid but about every 3 days now vs daily before. Your TA will come down with the acid additions and that will help, I am waiting for my one year mark to see if my acid demands dwindle, if they don't then I might add an auto dispenser like a Stenner Pump

 

[MichaelT20]

There will be a SWG installed pretty soon. I think my pool guy says a month is good for that. Sound about right?

There is a spa spillway that is currently running all the time. I am also told I can decrease the time running after a month.

It sounds like I should be buying the muriatic acid in bulk!

Thank you all for the help.

Yes it’s about a month after fill that you’re allowed to use salt and the swg so that sounds right.

With your spillway and swg you’ll be adding acid regularly (probably - every pool is different). The lower you get your ta the slower ph will rise. 50 is the bare minimum recommended here.

I usually add about 1/4 gallon once a week. It drifts up close to 8, adding a 1/4 - 1/3 gallon reduces it down to low 7’s. I then let it drift up again. Rain and other variables will affect it but on average I gain 0.1/day.

The new plaster is definitely thirsty. So tldr it’ll slow down after a couple months but you’ll most likely always need acid.

Recommend wearing gloves and goggles. You don’t want that stuff in your eyes