Pitting or scaling?

May 13, 2017
8
Poway/ca
#1
hi



I just had my pool resurfaced in January and have been pretty good about my chemistry however my TA and ph were running a bit low for about a month TA 60 and ph7-7.2. It's now 80 and 7.4

I however just converted to a swg and took off the pool cover this week to notice a bunch of spots all over. At first I thought scaling, Then undisolved salts. But after scrubbing fairly hard nothing smoothed out.

After looking at it closer I noticed tiny holes at the center of most of these spots. So I'm thinking it must be pitting.

Questions
1: what do you think? Pitting. Scaling? Or salt?
2: if pitting. Will this lead to larger problems overtime even if I keep my water properly balanced? Or is it just a visual thing at this point and as long as I keep things balanced I'm good?
 
Last edited:

kadavis

TFP Guide
In The Industry
Apr 5, 2015
1,439
tucson, arizona
#2
I believe they call it soft spotting now. Used to be called spot etching. There are a mutitude of opinions about the cause and who is at fault, I tend to believe in the same opinion as a research company known as On Balance. Maybe they will chime in on this
 
May 13, 2017
8
Poway/ca
#3
Kadavis. Thanks for your response. Just that keyword sent me down a worm hole of reading onbalances previous posts. It's very interesting and I think is exactly what's going on. It's very unfortunate.

I for one however don't mind surface variation at all really but what concerns me is whether or not this plaster will hold for the long haul and just look "ugly" or if this is just the beginning and it will not last that long?

I think if I can understand that I'll have a better idea for if I should pursue the builder replastering it or just show him so he is aware and move on.

Thanks!

I believe they call it soft spotting now. Used to be called spot etching. There are a mutitude of opinions about the cause and who is at fault, I tend to believe in the same opinion as a research company known as On Balance. Maybe they will chime in on this
 

pooldv

Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
24,993
DFW, TX
#4
Welcome to TFP!

What was your CH over that time period? If it was low, under 250ppm, then it is most likely etching. My plaster etched the first winter due to low CH and relatively low TA and pH. Yes, it will be fine and last a long time if you keep it balanced from now forward the etching will stop. Enter all your test results into PoolMath and it will give you a CSI score. If you have an SWG keep CSI between -0.3 and 0, if not then keep it between- 0.3 and +0.3, to prevent etching or scaling. More here, Pool School - Calcium Scaling
 
May 13, 2017
8
Poway/ca
#5
Hi pooldv thanks for the response.

My ch is and pretty much has been from start up 400. After calculating my csi score is -.1.

Any thoughts?
Thanks!

Welcome to TFP!

What was your CH over that time period? If it was low, under 250ppm, then it is most likely etching. My plaster etched the first winter due to low CH and relatively low TA and pH. Yes, it will be fine and last a long time if you keep it balanced from now forward the etching will stop. Enter all your test results into PoolMath and it will give you a CSI score. If you have an SWG keep CSI between -0.3 and 0, if not then keep it between- 0.3 and +0.3, to prevent etching or scaling. More here, Pool School - Calcium Scaling
 

pooldv

Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
24,993
DFW, TX
#7
What was the CSI when pH is 7.0, TA 60 and water temp at 40 or 50 or whatever it was during winter?
 
May 13, 2017
8
Poway/ca
#8
Looking back at my paperwork I'm not sure my ph has ever been that low actually. The worst I've seen that I can recall is a 7.4 ph at a 60 TA. I'm in San Diego so I doubt my water temp has gotten that low also.

What was the CSI when pH is 7.0, TA 60 and water temp at 40 or 50 or whatever it was during winter?
 
Apr 19, 2017
23
marlton/nj
#9
kinda looks similar to a problem I just got don't dealing with. however, mine did not leave any holes when I scrubbed them? are you sure the holes are into the plaster or is it possible that the holes are into a layer of scale that you think is plaster? have you used a pumice stone on this? (not all stones are the same, I found that the smaller rectangular grey ones that sink are much better than the large tan ones that float). my problem was scale and the stone removed it fairly easily. but the whole pool was covered so that wasn't a viable option. I lowered ph to 7.2 and held it there, and added scale tec. as per scale tec instructions, I turned off swg, held fc between 1.5-2 with bleach, and added algaecide 60. not sure what exactly worked the scale tec or lowering the ph but my problem is gone. here are pics of the walls but the floor that I couldn't photo was completely covered.


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