Fighting two issues

Autonoz

Bronze Supporter
Jun 14, 2017
48
Casa Grande, Arizona
17,000 gallon plaster diving pool. Using liquid chlorine and muriatic acid. Here are my issues. I am continually fighting rising PH. Checked it last night and it was 7.6, checked it this morning and it was 7.7. Adding acid every 2-3 days. second issue is itching after swimming. After doing research on here it says high PH will cause this. What is considered the itch level of PH? Where should I keep my PH at? If its at 7.8 and causing itching should I bring it down to say 7.5?
Current readings
FC 6
CC .5
PH 7.7 fill water 7.7 Adding replacement water regularly, but not every day and PH rises fast even without adding water
TA 60
CH 370
CYA 40 I also find with the Arizona sun and adding water regularly for evaporation my CYA drops fairly quick
 
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ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
10,794
Northern NJ
You using sulfuric acid or muriatic acid?

How do you measure pH 7.6 vs 7.7?

Losing water from evaporation does not cause CYA loss. CYA does not evaporate with the water. Your fill water replaces the evaporated water and you maintain the CYA level.

Lots of us run our pH around 7.8 with no itching.

After doing research on here it says high PH will cause this.
Where does it say that?
 
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Autonoz

Bronze Supporter
Jun 14, 2017
48
Casa Grande, Arizona
You using sulfuric acid or muriatic acid?
LOL! Muriatic acid

How do you measure pH 7.6 vs 7.7?
Seeing how my scale goes fro 7.6 to 7.8 if the color is in between its 7.7

Losing water from evaporation does not cause CYA loss. CYA does not evaporate with the water. Your fill water replaces the evaporated water and you maintain the CYA level.
If thats the case, how does partially draining your water lower your CYA. And why else would my CYA level drop?

Lots of us run our pH around 7.8 with no itching.
That's awesome



Where does it say that?
In one of the posts on here about itching it say a high PH can cause itching
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
10,794
Northern NJ
If thats the case, how does partially draining your water lower your CYA. And why else would my CYA level drop?
When you drain water the CYA flows out with the water fluid and is lost.

CYA does not evaporate with water evaporating. CYA stays in the water and your CYA level will increase with less water if you did not replace the evaporation.
 

PoolGate

Gold Supporter
TFP Guide
Jun 7, 2017
3,832
Damascus, MD
My pH is frequently 8 or more. I add acid weekly sometimes a gallon. Just part of my maintenance. No one ever has complained about itching though and I have never heard that either. How to you add chlorine? Manually? Your chlorine level is at the high part for your CYA of 40. If it was actually 30, then you are in the high range. Not that it would cause issues but perhaps those that itch are sensitive to chlorine. I suggest raising your CYA to 50-60 and see what happens.
 

Autonoz

Bronze Supporter
Jun 14, 2017
48
Casa Grande, Arizona
My pH is frequently 8 or more. I add acid weekly sometimes a gallon. Just part of my maintenance. No one ever has complained about itching though and I have never heard that either. How to you add chlorine? Manually? Your chlorine level is at the high part for your CYA of 40. If it was actually 30, then you are in the high range. Not that it would cause issues but perhaps those that itch are sensitive to chlorine. I suggest raising your CYA to 50-60 and see what happens.
Yes I do do add liquid chlorine manually. I usually Have my CYA between 50-60 it just happened to be 40 this last time I checked. It had dropped from the time I checked it before. I thought from evaporation and adding water. I will be raising it today. That is why my FC is kept at 6
 

duraleigh

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Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
32,859
Sebring, Florida
Correct.....you have two issues but they are unrelated. Solve them one at a time is the best method. pH is a good start

High pH or ANY pH within reason does not cause itching. I hope you did not read that on TFP as you say. Can you find it again?

A steadily rising pH is a characteristic of most pools.......no way around it. Do you have a spillover or waterfall that is causing aeration? That is the most common cause of rising pH and, of course, your fill water is fairly high to begin with so you don't have much wiggle room to stay in the 7's.

If you bring your pH down to around 7.6 (for example) how many days before it goes to 8.0?
 

Autonoz

Bronze Supporter
Jun 14, 2017
48
Casa Grande, Arizona
Correct.....you have two issues but they are unrelated. Solve them one at a time is the best method. pH is a good start

High pH or ANY pH within reason does not cause itching. I hope you did not read that on TFP as you say. Can you find it again?

A steadily rising pH is a characteristic of most pools.......no way around it. Do you have a spillover or waterfall that is causing aeration? That is the most common cause of rising pH and, of course, your fill water is fairly high to begin with so you don't have much wiggle room to stay in the 7's.

No aeration device

If you bring your pH down to around 7.6 (for example) how many days before it goes to 8.0?
About three days. I know rising PH is normal in a pool, but it just seems faster than it used to be and changing my TA has done nothing to slow it down. My biggest concern with the PH was if it was causing my itching problem when in the upper limits. I did read it on hear somewhere, I will look for the post. I also read it on other websites.
 

frogabog

Gold Supporter
LifeTime Supporter
Jul 16, 2010
2,833
Portland, Oregon
We'll correct that if you find it for us......it's wrong.
I actually remember seeing that recently, but can't seem to locate it with any kind of G searching for "itch", "itchy", or "itching". Someone did however say that high pH causes itching. I would think low pH might cause itching, but not high. Maybe the post got edited?
 

Autonoz

Bronze Supporter
Jun 14, 2017
48
Casa Grande, Arizona
I actually remember seeing that recently, but can't seem to locate it with any kind of G searching for "itch", "itchy", or "itching". Someone did however say that high pH causes itching. I would think low pH might cause itching, but not high. Maybe the post got edited?
Yes, all of my searching comes up with skin irritation from high PH. There is one that says itching, but that is for a spa with high PH and/or TA. I can not find the original one I read on here.