High pH - won't come down

pagreenpool

Well-known member
May 22, 2017
57
Allentown, PA
I've added bags of ph down, half a bag at a time... so far added two bags. I figured if the pH was red it was on the upper scale. It hasn't really come down. Am I reading this right that my ph is high? Just wanted to get a second opinion before I run out and get more ph down. All the other chemicals are in line but I just converted to salt and it's my first season. The salt is a little high at 4200

PXL_20230830_145300630.jpg
 
So couple things to think about...
  1. As @Texas Splash indicated use Muriatic. pH down adds sulphates which can damage your SWCG
  2. Reduce your pH in .4 increments. Test after 15 minutes, reduce again in .4. Rinse repeat until you get into the 7s. Use pool math to calculate how much muriatic acid to use to reduce pH by .4. Link-->PoolMath
  3. If your FC is 10 or greater the pH test is invalid. You need to let your FC dip below 10 before testing pH. When you FC is >10 it can look like the test you posted...
  4. How are you testing? (what kit?)
  5. Can you post a full set of results please? (FC, CC, CYA, CH, TA).
 
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Put the pH Down away. Instead, grab a couple bottles of muriatic acid (MA) and treat the pH with that. I think you'll find much better results with MA.

Remember the two enemies of an elevated pH and those are an elevated TA and aeration.

For the muriatic acid, any stuff will do? i.e.
There is no "pool" muriatic acid right?

Also when you say aeration do you mean too much or too little

So couple things to think about...
  1. As @Texas Splash indicated use Muriatic. pH down adds sulphates which can damage your SWCG
  2. Reduce your pH in .4 increments. Test after 15 minutes, reduce again in .4. Rinse repeat until you get into the 7s. Use pool math to calculate how much muriatic acid to use to reduce pH by .4. Link-->PoolMath
  3. If your FC is 10 or greater the pH test is invalid. You need to let your FC dip below 10 before testing pH. When you FC is >10 it can look like the test you posted...
  4. How are you testing? (what kit?)
  5. Can you post a full set of results please? (FC, CC, CYA, CH, TA).

Test kit is K-2006

Current water:
FC 5
pH 8+
TA 60
CH 270
CYA 50

Thank you both for your help
 
For the muriatic acid, any stuff will do? i.e.
You'll find MA at the pool store and hardware stores in their pool section. The MA in the pool sections is usually the 31.5% (20 Baume) strength that you want. The stuff in the paint section may only be half strength (low fume).
 

At your Allentown store....normally its stored outdoors in the garden landscape/pool section
 
Aeration will raise pH.

I have been running my 2 hp pump 24/7 for the past 3 weeks since I am adding chemicals and what not. I've been meaning to set it on a schedule. I was a little reluctant to do so because I have no fail safe on the SWG right now besides the flow detector attached to it which I've heard isn't 100% reliable. I was going to install one of those amp sensor cut off switches to detect low amps to the pump and kill the SWG and heater. Just haven't gotten around to it yet.

Perhaps the 2hp pump (25,000 gallon) pool is circulating too much leading to the high ph?
 
Originally put in 20 years ago, just did a large renovation
Just circulating water won't raise pH.

Waterfalls, bubblers etc. will.

How old is the pool? What type of pool is it? Maybe fill out your signature would help...

Ok... so that wasn't the culprit. The pool is 20 years old but we just did a large renovation. New liner, equipment, convert from chlorine to salt.

Did fill out my signature, thanks for the reminder.

Not really sure why the pH got so high. I dumped 20 bags of salt in originally. I was messing with the SWG trying to get the right setting. At some point the chlorine was low, as in none. Instead of being patient and tweaking the SWG I decided to drop two chlorine tablets in each skimmer. 24 hours later my chlorine was 10 and I took them out. Doing the tablets was a mistake I am guessing... as I should have let the SWG do it's thing. I think that may have left the salt too high and screwed up the pH as well?
 

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The salt too high was likely because of the exiting salt level in the pool before you converted. You should test before adding salt. Mine was 2200 when I converted...didn't need to add a full salt load.

Not sure on the pH. With a TA of 60, your pH should be fairly stable. How old are your reagents?

You should always RAISE FC with liquid chlorine and use SWCG to maintain FC.
 
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