Concrete coping stains/holes?

[Sam8407]

Hey all.
Searched and could find keywords for this. Pool is under 2 years old and the concrete coping is staining (pool builder obviously did not seal it) and holes/chips are forming randomly. I’m assuming something in the pool water is slowly eating away when splashing on it. Any ideas on preventing further problems? I’m scared if I leave it the concrete may crack over time.

 

[Texas Splash]

Two years? Wow. Either a questionable job by the contractor or some crazy chemistry nearby. I'm leaning towards the quality of the installation, but to be safe, can you provide us with a full set of water test results?

Is your contractor even in the discussion?

 

[Sam8407]

Thanks for the response. I’m thinking it has to do with high CH levels. My tap is fairly high as well. Here are my readings from today. I forgot to top off chlorine after this past Saturday.

FC 2.0
PH 7.8 (I try to keep it around 7.4-7.5)
TA 80
CH 710
CYA 70 (tad higher than I like)
Temp 80

My plan to lower CH is to slowly drain-refill this fall as the rainy season comes back.

 

[Texas Splash]

If those are your own test results, other than a low FC and slightly elevated CH level, they aren't bad. I would increase the FC right away and keep balanced to your CYA as noted on the FC/CYA Levels. As for the concrete, we see many people whose elevated CH causes problems, but your dark stains look unique to me. Hard water also would not result in pitting.

 

[Sam8407]

Just loaded up the liquid chlorine.
Good thing is the pool company is going to be fixing some tile work tomorrow so I will bring it up and see what they say.
Thanks again for the insight here!