Plaster question

cybertoad

Active member
Jan 30, 2019
30
California
Hello, we just had our new pool plastered on July 31st. We have been brushing the pool religiously as recommended. Tonight I was looking near the main drains and saw what appears to be an area of plaster that is rough and pitted. I haven't dived down to the bottom of the pool to feel it yet, but when lightly dragging the end of the skimmer pole over the area it appears to catch. There is also discoloration which seems to be getting worse. Our pool startup tech tells us that this is just efflorescence and can be cured with an acid treatment after the plaster has sufficiently cured for a few months. My gut instinct is that there is something wrong with this plaster in this area though. Any thoughts would be appreciated. I will dive down tomorrow morning to look at it up close. If those are indeed large pitted areas, is that a substandard issue that the plaster company should resolve?
 

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ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
7,876
Northern NJ
Efflorescence comes from water passing though concrete/gunite and carrying salts out. There should be no water flowing into the pool to cause efflorescence. You see that on the outside of pool shells.

I am concerned it is around and between the main drains. Is something leaking in the drain or plumbing in that area?

An acid wash may fix things cosmetically but if there is an underlying problem it will return.

Talk to your PB, not the tech.
 
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cybertoad

Active member
Jan 30, 2019
30
California
I dived down to the bottom of the pool, what I thought was pitting was more of a trowel mark or something that was a different color. I think the area around the drain that has the largest color variation was due to the hoses being immediately put in the pool after plastering. That was where the two hoses sat. Pool builder is putting some acid in the pool to try and clear that up. We will see how it resolves. The mottling in that area actually looks much worse on the nighttime picture than it does in the daytime. I will submit more pics upcoming.
 

cybertoad

Active member
Jan 30, 2019
30
California
UPDATE: I talked with the builder today who stated this type of color variation is a "normal occurrence" of the finish due to being a cementitious product but stated they will work to reduce the appearance of the mottling. We have had a good experience working with this pool builder, so I am hopeful that this will get resolved to our satisfaction.
 

JamesW

TFP Expert
Mar 2, 2011
15,567
That looks pretty blotchy. What equipment do you have?

What is the chemistry history from fill to now?

If you have a cartridge filter can you remove the cartridge and get a picture before you clean it?
 

cybertoad

Active member
Jan 30, 2019
30
California
It's actually looking less blotchy to me after they added some acid to the pool for a couple of days, which helped get rid of some of the plaster dust. Not really noticeable in daylight. I'm not sure if there was some water entrapment or what. Majority of the other areas of pool are very uniform in color. We cleaned the pool filter yesterday, sorry I didn't get a chance to snap a picture, and it was caked with so much plaster dust that we ended up having to soak the filters in acid for a bit to get them clean. We have all Pentair equipment and Pentair cartridge filter. Once plaster has cured for a few more months and swimming season is over, we will do a zero alkalinity treatment which they think will darken everything to be more uniform.

As to chemical history, nothing other than acid, sodium bicarbonate and calcium chloride, I believe. I'm taking over chemistry today. This is my first pool, but I bought a TF-100 test kit and reading up. TA is at 80 now, and no chlorine or stabilizer added yet. CH at 180. Planning to add CYA and chlorine shortly and monitoring pH.
 

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