Can't lower PH

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R

Ron55

Bronze Supporter
Jun 23, 2013
90
SW Florida
I have been trying for the past several days to lower my PH. The test kit reads 8.2.

Here are my other numbers for my 10,000 gallon gunite, SWG pool

FC 7.0
CYA 60
TA 100
Ph 8.2
Calcium 300
Salt 3400

Pool Math says I should add 14 oz of 31.45 - 20 Baume Acid

Only problem is I have added 16 oz so far and it hasn't lowered it. It is possible it is above 8.2 as that is as high as the test kit displays.

Suggestions?

I'm going to add another 14 oz. later and test again.
 
How old are your reagents in your test kit?

pH 8.2 is the max reading and your pH could be higher.

If you are confident your reagents are good then keep adding 10-14 oz of MA, test after 30 minutes, and repeat until your pH is in the 7's.
 
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ajw22 said:
How old are your reagents in your test kit?

pH 8.2 is the max reading and your pH could be higher.

If you are confident your reagents are good then keep adding 10-14 oz of MA, test after 30 minutes, and repeat until your pH is in the 7's.
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Thanks. I just received my test kit last month from TFTestkits so I am assuming the reagents are new.
 
I've been adding muriatic to get the PH down to 7.6 but the next day it is back to 8.2

Today after the storm the color was so dark that it was easily 8.2+

Here are the rest of my numbers.

Ph 6
FC 6.0
CC 0
Cal 275
Alk 90
Salt 3500
CYA 40

I will add stabilizer to bring the CYA up but is it normal to have to add muriatic acid every other day to keep the Ph in range?
I probably need a new salt cell but have able to get it to keep producing chlorine by resetting salt reading when I run the diagnostic to 3400. Could that be causing it?
Could algae in the pool cause the high Ph? I plan to run a OCLT tonight.
 
Ron55 said:
I will add stabilizer to bring the CYA up but is it normal to have to add muriatic acid every other day to keep the Ph in range?
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Maybe. As your TA comes down to 60-80, your pH rise will slow. When you get in that range, don't force it to 7.6. It may settle nicely at 7.8.
Ron55 said:
I probably need a new salt cell but have able to get it to keep producing chlorine by resetting salt reading when I run the diagnostic to 3400. Could that be causing it?
Click to expand...
No
Ron55 said:
Could algae in the pool cause the high Ph? I plan to run a OCLT tonight.
Click to expand...
No
 
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I would lower your TA to 70 or even 60 if that's not quite enough - and see if your ph is more stable in the high 7s. For our purposes, within the typical 7-8.2 testing range, the exact ph number is mostly just relevant to calculate your LSI/CSI to prevent corrosion/scaling. The idea that ph in the high 7s reduces chlorine efficacy is almost entirely untrue *in pools with CYA*.

Easiest way is to just use the Pool Math app to make sure your CSI is in range at a given ph/TA combination, so you could be as low as 60 TA with a ph of 8 and have a CSI right at 0 (ideal), or at 60/7.8 you're at -0.22, at 70/7.8 = -0.13, at 70/8 = 0.07 etc... All are great numbers (CSI -0.3 to +0.3 is ideal).

I do also controversially like borates (boric acid) which stabilize your ph for longer periods of time (same acid overall) and lower your CSI allowing for even more flexibility of a higher ph.

I went through exactly what you describe and the combination of lowering TA and adding borates eventually brought me to where I could add acid every 5ish days and keep ph within 0.2 - 0.3 or so of the target. I did eventually put together a cheap acid tank/pump setup last month for under $150 that has entirely eliminated having to mess with ph swings, but I would get your numbers in check first and see what you think.
 
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ajw22 said:
That is the cause of your pH rising so much every day.

Aeration from the water features causes pH to rise.

Aeration - Further Reading

www.troublefreepool.com www.troublefreepool.com

Do you have automation that can control your water features?
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No automation. But I can manually shut off the valve that controls the spillover.

I had read it could cause a rise in ph but I didn't realize that much.

I have added muriatic acid and shut off the valve. Let's see what that does.

Thanks.
 
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Don't let your spa water get stale and get algae.

If you are home and can run water through the spa in the morning and early afternoon twice a day for about 15 minutes.

Or keep a small flow running through the spa. The less the spillover water splashes int he spa the better to prevent aeration.

Is your pool in a cage or outdoors fully exposed to the sun?
 
ajw22 said:
Don't let your spa water get stale and get algae.

If you are home and can run water through the spa in the morning and early afternoon twice a day for about 15 minutes.

Or keep a small flow running through the spa. The less the spillover water splashes int he spa the better to prevent aeration.

Is your pool in a cage or outdoors fully exposed to the sun?
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It's in a cage, but it gets a lot of sun.
Eventually I'd like automate it, but in the meantime I can manually run it in the morning and early afternoon. When I can't I will let it run at a small flow.
 
Rechecked water after adding acid.
ph is down to 7.5
I'll recheck tomorrow with the spa spillover off and see if it maintains the ph.

I also noticed the accumulation of a white powder in the spa. I don't see it in the pool or see anything when I brushed the pool.

The pool has a pebbletec coating and does not seem to be degrading,

Could it be undissolved conditioner or calcium? And why only in the spa and not the pool?
 
What speed are you running your spa spillover?
 
ajw22 said:
Run your spillover at a slower RPM to create less aeration. See what speed gives you more then a trickle but not Niagara Falls.
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Thanks Allen.

The ph this morning was still 7.8 which I guess proves the point that the rising ph is from the spa spillover.

I've since change the daily rpm I am using on my pump as recommended on another thread.
I am running the pool at 1700 rpm. If I leave the spa valve halfway open at that speed I sill get some spillover and circulation in the spa. I will try that twice today for 15 mins and see how the ph responds.
My only concern is that at 1700 rpm I am getting some bubbling out of one of the pool jets and in the spa and I am hoping that doesn't add to the ph issue.
Again, thanks for the help.
 
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