New gunite pool, issues with chemicals and plaster

[OKLagoon]

Construction of our 15000 gallon gunite pool ended about a month ago. It has a salt water chlorine generator, but the salt hasn’t been put in yet. We brushed it twice a day for 2 weeks. The plaster is supposed to be Pebblefina Acquos, but it doesn’t look like it, and I don’t think the flecks were sprinkled into it during plaster. It looked pretty blotchy and still does. We did not get into it until a week after plaster and were very gentle on it during this time. The pool builder hired a maintenance company to take care of chemicals for two weeks. They only came 3 times in those two weeks. After their last visit, I tested the water with the test kit the builder gave us. There was no chlorine in it, the pH was over 8 (that’s as high as the kit reads), and the TA was 110.

I wasn’t sure if those results were valid, because the kit had been left outside for a while. I went and bought the Taylor K2006 and the test results were the same. I did not elect to hire the pool company after this, because they did not add anything during their final visit, when it clearly needed chemicals.

I added about 1/3rd gallon of chlorine that evening, and it was gone the next day. I also added muriatic acid by diluting into a bucket and pouring around the edge of the pool, then brushing to stir and clean the plaster. After doing this, we noticed even more white blotchy staining the next day.

We then went on vacation and I simply told the person staying at our house to check chlorine levels and add a half gallon when low. It consistently is gone almost as soon as it’s put in.

Question is, does the plaster blotching go away? I tested CYA today and there’s none. Any suggests for adding?

Sharing my pool info here from Pool Math:

==========================================
Oasis
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Build Type: Plaster
Volume: 15000 gallons
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Latest Test Result Summary:
FC: 0.0 (13 minutes ago)
CC: 0.0 (13 minutes ago)
pH: 8.2 (13 minutes ago)
TA: 110 (13 minutes ago)
CYA: 0 (13 minutes ago)
TEMPERATURE: 80° (14 days ago)
==========================================
------------------------------------------
Test Results 06-25-2023 @ 09:08 PM
------------------------------------------
Free Chlorine: 0.0
Combined Chlorine: 0.0
pH: 8.2
Total Alkalinity: 110
CYA: 0

 

[ajw22]

Welcome to TFP.

The plaster blotching will not go away.

Plaster Installation and Maintenance - Further Reading

www.troublefreepool.com

Your lack of CYA is why your chlorine is rapidly being consumed by the suns UV.

What Are My Ideal Pool Levels?

Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.

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The Free Chlorine and Cyanuric Acid Relationship

Managing your cyanuric acid and Free Chlorine levels is key to stabilizing your pool. Learn how these two items affect each other.

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Your one-stop shop for all things TFP to include: ABCs of Water Chemistry, Recommended Chemicals/Levels, Test Kits, Troubleshooting, and much more!

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[bradgray]

Everything Alan said. And be ready to up your chlorine to half or full gallons until you reach and sustain the proper FC levels. 1/3 is hardly kindling for a 15k pool that has no cover or is getting used often.

Eventually the SWG should handle 99% of your chlorine needs if sized properly and dialed in correctly. Keep some gallons on hand to use in emergencies and periods of unusual usage/impact.

Also gear up for a lot of acid. New plaster and SWG will chew through a lot in the beginning.

The best way to dose CYA is to buy the stabilizer pure, do the math, and hit your target from day one. But I will, from time to time on a new pool, use dichlor shock to kill 3 birds with the same stone (lower ph, chlorinate, add CYA). But you have to be calculated about it so this isn't for novices, and isn't generally accepted as a good method for most.

 

[cdadams1223]

I’d start by adding 5ppm of liquid chlorine (LC) ASAP each day since you have zero CYA to protect it from the sun. That’s 96oz of 10% LC or 77oz of 12.5% LC.

Then, by using the sock method, use granular CYA (60oz) to get it up to 30ppm. Your FC levels will hold until you can dial your CYA to I believe 60-80ppm per the PoolMath app for a 15K gallon pool.

Once you get salt in the water and eventually get your SWG going, you can get that dialed in to use less LC over time.

 

[OKLagoon]

Thanks all. I will get to making these changes. I am curious about the blotching, is this a problem the installer caused? I have a one year warranty with the builder, and have sent an email about it today.

 

[ajw22]

Thanks all. I will get to making these changes. I am curious about the blotching, is this a problem the installer caused? I have a one year warranty with the builder, and have sent an email about it today.

You can discuss it with the builder.

Mottling or blotching of plaster is considered normal quality now.

The builder will offer to do an acid wash which will remove a layer of your plaster and weaken it. We do not recommend acid washes for cosmetic problems but it is your pool and you can decide.

 

[OKLagoon]

You can discuss it with the builder.

Mottling or blotching of plaster is considered normal quality now.

The builder will offer to do an acid wash which will remove a layer of your plaster and weaken it. We do not recommend acid washes for cosmetic problems but it is your pool and you can decide.

Thanks. The PB and plaster company owner visited a couple of days ago. The plaster guy admitted there were flaws in it, but (and honestly, in hindsight, wtf?) explained it away as workmanship issues between individuals on the team and the nature of working with plaster.

The plaster guy talked about draining the pool at the end of the season and scouring it with what looked like a rotary pad. Later, the PB sent me a message saying they believe a no-drain acid wash would help. Based on everything I've read here, I am very hesitant to agree to either of those things.

I still owe them a little bit of money. Ideally, I want them to discount the price of the pool and allow me to withhold a portion of the final payment, because we are planning to just deal with it. I don't want to have to replaster the pool years earlier than it would have been done because of the cosmetic issues, but they are significant.

 

[ajw22]

If you can live with it then do that.

Otherwise the rotary sanding is preferable to an acid wash.