Coping + Calcium (?) Issues

[zollan23]

My pool was installed in July 2021 so this is my 2nd "winter" (in quotations because I'm in Southern California and the pool never closes.

In the past few months my coping has this white discoloration that I suspect is efflorescence. Calcium deposits are much harder and almost like rock but efflorescence is more chalky and flaky... Correct me if I'm wrong.

Few questions.
1. What is the best way to remove this? Will a power washer do it? Muriatic acid? 50/50 white vinegar/water?

2. Is there something off with my chemistry that is causing this?

I've never managed the pool with anything other than the TFP method and my CSI is 95% within -0.30 - 0.30. I've never had algae, never had CC above 0.50 and always in balance. My TA always creeps with SwG + Plaster but it's always under control.

I've never added anything to my pool other than acid and salt (and borates). So why is this all of a sudden happening?

Appreciate the help.

 

[zollan23]

My pool was installed in July 2021 so this is my 2nd "winter" (in quotations because I'm in Southern California and the pool never closes.

In the past few months my coping has this white discoloration that I suspect is efflorescence. Calcium deposits are much harder and almost like rock but efflorescence is more chalky and flaky... Correct me if I'm wrong.

Few questions.
1. What is the best way to remove this? Will a power washer do it? Muriatic acid? 50/50 white vinegar/water?

2. Is there something off with my chemistry that is causing this?

I've never managed the pool with anything other than the TFP method and my CSI is 95% within -0.30 - 0.30. I've never had algae, never had CC above 0.50 and always in balance. My TA always creeps with SwG + Plaster but it's always under control.

I've never added anything to my pool other than acid and salt (and borates). So why is this all of a sudden happening?

Appreciate the help.

Sorry. Meant to include picture

 

[ajw22]

Efflorescence does not flow up like that. Efflorescence is created by water flow carrying salts and minerals out of stone and water does not flow up.

Efflorescence - Further Reading

www.troublefreepool.com

That looks like waterline scale.

Start with the least damaging treatment first. I would not use acid or vinegar on stone as it will stain the stone. You cannot treat this like it is on hard tile.

I would try power washing with just water.

Your salt level of over 4000 is very high. This looks like salt from evaporation.

What is your salt level and how are you measuring it?

 

[zollan23]

I'm using the Taylor salt kit. It's been a while since I measured so I will do that and report back. Really hoping it comes off with just a power washer.

Given my water is 57 degrees, should I let it come to room temp before measuring the salt or does it not matter?

 

[ajw22]

Given my water is 57 degrees, should I let it come to room temp before measuring the salt or does it not matter?

Should not matter but can not hurt to let the sample warm before testing.

 

[JoyfulNoise]

What is the coping made out of? Natural stone? Cast concrete?

Has it rained lately ?

 

[JamesW]

Check with the builder to see what they say.

It might be efflorescence if the ground is always wet because the stone or concrete can absorb water and the water can come out of the top of the stone and cause efflorescence.

Is your local ground always saturated with water?

 

[JamesW]

Do you have pictures of the original look?

Try some distilled water and a soft plastic bristle scrub brush to see if that helps any.

 

[JamesW]

Do all stones have the same issue or only some sections?

Do you have pictures of everything?

Does the deck drain properly when it gets wet?

Is there an expansion joint behind the coping between the deck and the coping?

 

[zollan23]

What is the coping made out of? Natural stone? Cast concrete?

Has it rained lately ?

Yes and yes...

 

[zollan23]

Do all stones have the same issue or only some sections?

Do you have pictures of everything?

Does the deck drain properly when it gets wet?

Is there an expansion joint behind the coping between the deck and the coping?

Thanks for the questions. Iv

Do all stones have the same issue or only some sections?

Do you have pictures of everything?

Does the deck drain properly when it gets wet?

Is there an expansion joint behind the coping between the deck and the coping?

Thanks for the questions. I'm attaching two pictures. One shows what the non-affected coping looks like and the other is just the entire pool.

Not all areas are impacted however I'd say about 75% of the ground level coping is. The raised wall and raised spa coping has no issue. Like zero impact.

I feel like everything drains well, yes. I never have an issue with pooling water or anything like that.

I'm not sure what you mean by expansion joint? You can see in the close up picture the seal between the coping and pavers... Just standard deck-o-seal to my knowledge.

Lastly, I just tested the salt with the Taylor K-1766 and I'm at 4,000. I think that's a pretty good spot considering 3,800 is my ideal.

Thanks in advance for any additional advice.

 

[JamesW]

Since the issue is only on the ground level coping, I suspect that the ground is wet and the water is wicking up through the stone and causing efflorescence.

That's hard to verify without pulling up a coping stone to see if it is wet below the stone.

Try scrubbing with distilled water and a soft bristle brush.

What material is the stone?

If you can collect some of the deposit, you can put it in a liter of distilled water and then test the water for salt and calcium to see if either reading is higher than zero.

 

[zollan23]

It's just regular concrete. Will try to just brush with water and see what happens. Is there any way to prevent this?

 

[JamesW]

Is there any way to prevent this?

If it's water wicking up from the ground, you would have to keep the ground dryer by improving drainage.

It is difficult to verify for sure without pulling stone in the deck or coping to see how wet it is.

It might be from water splashing up and then drying and leaving behind whatever dissolved solids were in the water.

It's hard to tell for sure from pictures.

 

[ajw22]

Lastly, I just tested the salt with the Taylor K-1766 and I'm at 4,000. I think that's a pretty good spot considering 3,800 is my ideal.

I would run your salt in the 3000-3400 range. 4000 is getting too high.

The iChlor Installation Manual says:

• 3600 ppm of salt is recommended for optimum water condition.
• Low salt concentration below 3000 ppm will reduce operating efficiency.
• Low salt concentration below 2600 ppm will cause the unit to reduce production.
• Low salt concentration below 2000 ppm will cause the unit to turn OFF.
• High salt concentration above 4500 ppm may cause excessive corrosion or deterioration to pool equipment and surrounding surfaces in and around the pool.

 

[zollan23]

Thanks for the help as usual, everyone. After some recent rains it seems like this problem just went away. Once the rain hit and it dried the white turned into very flakey particles that almost looked like light snowflakes. Just kind of washed away.