Calcium hardness and pitting, raise CH?

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C

Contentt

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May 18, 2018
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Vienna, VA
Year 2.5 of SWG pool ownership and I noticed some pitting on the plaster pool wall near our flagstone waterfall that has always shown signs of calcium buildup. Believe I should raise my Calcium Hardness, here are my latest test results. Is using Ice Melt like this from Lowes if I can find it the best way to raise CH? We're hoping resurfacing is a ways off, but the pool is 14 years old. And I need to bring my CYA up a bit.

FC: 6
CC: .5
PH: 7.5
TA: 110
CH: 325
CYA: 60
Salt: 3400

Thanks.
Dave
 
I plugged your numbers into poolmath and tried a few different temperatures and then looked at what pH changes will do. You're neutral now, but if you drop pH to 7.2, you'll see it approach dangerous territory. I would keep pH at the upper end of acceptable, 7.5 and above.

On the other end, though, since it's right by the waterfall, where the pH is going to be high from all the aeration, it could be localized scaling. Is it really pitting, or could it be raised a little? Scale feels like sandpaper.

Calcium additions are not something I'm familiar with. I deal with Calcium buildup, so I've never added. I'm also sort of biased against it because I see mine rise week after week all summer long from evaporation and refilling. Maybe you get rain in the summer, so that's not your experience.
 
Thanks for the input. I'm pretty confident I have a few pitted holes in the plaster, doesn't feel raised. I constantly battle calcium buildup on the tile under the waterfalls and on the flagstone. Pool temp is 78, we do get rain in Virginia frequently this time of year with thunderstorms, rained today for 30 minutes.

Pool math shows I'm Balanced (-0.21 | -0.18). So perhaps CH is fine and pool liner is just getting old?
 
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Pitting and calcium build up don't match. Pitting occurs when calcium is leached from the pool walls because the water has too little......scaling is when the water has too much.
 
I think OP means to say "pool surface" instead of "liner".

Nevertheless, pitting and calcium build up are opposite problems and we need some clarification as to the issue before stabbing at guesses, OP reports CH of 325 which is neither too high or too low. Got a pic(s), OP?
 
Thanks, I don't have the lingo correct. Here's a picture of what I'm trying to understand, I'm concerned about the 4-5 dark gray areas under the water line and trying to figure out if the water is out of balance and contributing to a problem. 105746
 
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I can't tell much about the dark areas because of the pic quality. Guessing it appears your plaster has chipped off which you can readily verify by touching those areas.

Incidentally, the white streaks running down your tile is efflorescence, Water from behind that rock is migrating to the surface, depositing that white stuff on the tile as it evaporates.
 
Thanks, yes I believe the plaster has chipped off. So is this just due to age of the pool, or is my CH at 325 contributing? It sounds like my CH is not an issue and it's just an old pool, but looking for smarter people than me to confirm :)

And thank for the efflorescence tip. I've been fighting it with acid but I"m loosing, seems my only option is to live with it, or do something about the garden bed/retaining wall that is behind my flagstone waterfall. I'll do some searching but if anyone has suggestions I'm all ears.
105808
 

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See post #2. CH level does not effect plaster. Level of CSI does. Not much you can do except to replaster once it is chipping off.
 
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