Natural marble & calcium noodles

[jesper]

We completed construction of our pool last summer, this weekend we swam for the first time this year. I noticed some calcium noodles around the marble steps, one large one I crushed with my fingers - it was very white rock like, some larger pieces, but also lots of fine dust that I could not collect as it just dispersed in the water.

I tried taking some pictures of a couple of smaller ones, these as well as the larger that I crushed all appeared in grouting between pieces of natural marble (Aliveri Grey Marble), or between the marble and the plastered (beadcrete) surface.



An overview of the steps and the rest of the pool



I came across Calcium Nodules in pools and it looks plausible it is the same, but a cavity on the back side of the marble pieces, with the marble dissolving slowly.

In this case, would the recommended solution be to find and fill the tiny holes with epoxy ?

How about dissolving marble from the steps them self ? Is that something I should be concerned about ?

I have a Taylor 2006 test kit, these are the most recent measurements.
FC 16
CC 0.5
PH 7.3
TA 90
CH 500 (but not sure I can trust this, see below ...)
CYA 50
Salt 3200
TEMP 27 degrees C or 81 degrees F
CSI -0.22

I had some cloudy water about a week ago, so I did a SLAM that is the reason for the high FC.

I've always found it difficult to get a reliable Calcium Hardness reading, it doesn't chance colour clearly, but I get a purple colour, and I find it difficult to know when to stop counting, I tried adding a few drops of the hardness reactant as suggested in the manual, but I still see a fading end point.

Any ideas here ?

 

[ajw22]

You have efflorescence coming out between your grout lines.

Grout Efflorescence in Several Areas

I have Grout Efflorescence occurring in several areas of the tile wall (above the water line). It only occures on the "higher" side of the pool. The lot has a heavy slope and one wall of the pool is higher, holding back this area. It appears that ground water is leaching thru the tile/grout...

www.troublefreepool.com

Calcium Hardness Test Interference - interference from copper and iron can cause a fading endpoint and some color changes before the final endpoint.

See the video in

General Test Interferences

www.taylortechnologies.com

 

[jesper]

You have efflorescence coming out between your grout lines.

Grout Efflorescence in Several Areas

I have Grout Efflorescence occurring in several areas of the tile wall (above the water line). It only occures on the "higher" side of the pool. The lot has a heavy slope and one wall of the pool is higher, holding back this area. It appears that ground water is leaching thru the tile/grout...

www.troublefreepool.com

It is possible, but I find it surprising if that is the case. The concrete shell is cast in one piece with a water proofing mixed in the concrete (https://www.penetron.com.cy/index.php/el/pds/542-penetron-admix-pds-eng/file), it was then treated with a water proofing layer before the marble pieces were placed.

In general the soil is very dry here, we have a climate similar to Southern California, little rain and only from Nov to April. However, over the winter we did have a water pipe leaking, that resulted in the soil behind the marble steps being soaked for months. This was fixed early March.

I guess if I clean the calcium deposits now, and they do not return, it most likely is efflorescence. However if they do return, do you think it is possible it is caused by cavities in the grouting, causing calcium saturation ?

Calcium Hardness Test Interference - interference from copper and iron can cause a fading endpoint and some color changes before the final endpoint.

See the video in

General Test Interferences

www.taylortechnologies.com

That is what I've tried, based on the text from the manual I quoted. I tried with 5-6 drops of R-012 first, but when that didn't work I tried with 10 drops, and I still see a purple colour.

I'll try again with a new set of reactants from a TF100 kit I got.

Thanks a lot for getting back to me!

 

[jesper]

That is what I've tried, based on the text from the manual I quoted. I tried with 5-6 drops of R-012 first, but when that didn't work I tried with 10 drops, and I still see a purple colour.

I'll try again with a new set of reactants from a TF100 kit I got.

Thanks a lot for getting back to me!

Got the TF100 kit out and redid the test, still see purple before eventually it turns blue. Redid it again and recorded a video

It eventually turns blue after 26 drops, but it was purple from around 19-20 drops. This was a 10ml sample so the 6-7 drops corespondents to a 150-175 range, or about 25%

 

[mknauss]

Be aware - you are squeezing the reagent bottles too much and the drops are streaming off the tip. Thus the drops are too small. You should be barely putting any pressure on the reagent bottle at all. The drops should form and fall naturally.

 

[jesper]

Be aware - you are squeezing the reagent bottles too much and the drops are streaming off the tip. Thus the drops are too small. You should be barely putting any pressure on the reagent bottle at all. The drops should form and fall naturally.

Thanks! I'll be careful going forward.