SWG pool. PH keeps increasing

Woodsy27

Active member
Mar 17, 2020
34
Thailand
Hello all.

I have a new pool 12000 gallons and im having problems keeping the PH stable.
7.4 then 3 days later it's up to 7.9.
So I add acid to take it back down to 7.4.
TA 120
CYA was 50 for the last 7 days now 150 plus?
I thought it was because maybe the SWG was producing maybe too much Chlorine and thus was helping increase the PH levels.

Any advice would be greatly appreciated.

I noticed on other threads maybe get Auto chemical feed for the Acid.

Regards
 

wireform

Silver Supporter
In The Industry
Aug 15, 2017
1,571
Spring Valley, NY
You need to fill in your signature so we can see what equipment you have. How are you testing and anything else you can offer giving us more history on your pool.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
19,437
Bedford, TX
27,

Most SWCG pools like their pH to be about 7.8.. You have two issues, your TA is 120 and you have a new pool. It takes months for new plaster to stop increasing your pH.

I would only add enough acid to drop your pH to 7.7 and then let it get to 7.9 or 8.0 before dropping it back to 7.7. Over time the TA will come down and that will help stabilize your pH.. TA can be as low as 50, so do not worry about it going too low.

Thanks,

Jim R.
 

Woodsy27

Active member
Mar 17, 2020
34
Thailand
Thanks Jim,

I'm just going off my test strips kit which says (TA 120 is ok). But thanks and hopefully in time it will come down.
My SWG manual says PH should be between 7 and 7.6.
So maybe every couple of days when PH rises I will need to add acid to bring levels back down? ( Or I should look into a Auto chemical pump).
What would you suggest for the Chlorine level to be in a SMG pool, as I've read and been told many different things.

Thanks
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
19,437
Bedford, TX
27,

It might be hard for you to obtain a good test kit in Thailand...

A chlorine level of only .3 very low.. To know what your Chlorine (FC) level needs to be, you need to know what your CYA level is first.. And then use this chart.. use the Saltwater part of the chart.. FC/CYA Chart

Thanks.

Jim R.
 

Woodsy27

Active member
Mar 17, 2020
34
Thailand
Yesterday I added Acid to bring PH down to 7.6.
Tested again today and back to PH .7.8.
How much acid is it safe to put in a pool in 1 day....
My SWG doesn't seem to like 7.8 as it keeps turning off..
I was wanting to bring PH down to 7 and hopefully lower the TA as well.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
19,437
Bedford, TX
27,

I don't know of any SWCG that shuts off due to any pH level.. You do understand that a SWCG will run and then turn off and then run again, based upon the percentage of output.. ??? So, basically, if the output is set to 50%, then the cell will only be on about 50% of the timer.. The exact length of the on/off cycle depends on the salt cell itself.. At 50% mine is on for 2.5 minutes and then off for 2.5 minutes. Some cells have cycles of up to 1.5 hours or so.

If your cell is shutting off, it is not due to the pH.

Some here have had good luck with digital pH readers, me, not so much.. Unless you constantly calibrate them, they will lead you down the wrong path. Just because it is digital, does not mean it is correct.. :mrgreen:

Thanks,

Jim R.
 
Last edited:

Woodsy27

Active member
Mar 17, 2020
34
Thailand
27,

I don't know of any SWCG that shuts off due to any pH level.. You do understand that a SWCG will run and then turn off and then run again, based upon the percentage of output.. ??? So, basically, if the output is set to 50%, then the cell will only be on about 50% of the timer.. The exact length of the on/off cycle depends on the salt cell itself.. At 50% mine is on for 2.5 minutes and then off for 2.5 minutes. Some cells have cycles of up to 1.5 hours or so.

If you cell is shutting off, it is not due to the pH.

Some here have had good luck with digital pH readers, me, not so much.. Unless you constantly calibrate them, they will lead you down the wrong path. Just because it is digital, does not mean it is correct.. :mrgreen:

Thanks,

Jim R.
Thanks for the info.
I wrote it wrongly, as I understand it turns off and on when required, but previously when PH was at 7.6 the SWG would be working ok.
Now it seems when the PH is 7.8 or above there are 2 red LED lights displaying , which in the manual States
"low or no salt" - Add salt to pool
"PH value too high"- Check the water PH value and keep it around 7.0-7.6.

As only the PH level had changed from yesterday , then I assumed it was that problem.
Nobody was swimming yesterday so I thought the Salt must be the same.

Thanks for your help and advice, much appreciated.
 
Last edited:

Woodsy27

Active member
Mar 17, 2020
34
Thailand
Latest update.
I have followed the guidelines from the forum
I lowered PH to 7.4 and this also lowered TA to 80
I added Chlorine to bring FC to 3
CYA is about 50 but my test strip is not that accurate it seems.
SWG is working and producing Chlorine.

I think the main reasons I was having problems was staying in the guidelines of the test strip. Which conflicts what TFP people say.. So im following TFP now ..

Thanks
 

wireform

Silver Supporter
In The Industry
Aug 15, 2017
1,571
Spring Valley, NY
Seems odd to me that the TA now is 80. You couldn't have put that much MA in the pool as the PH would drop much lower then 7.4. Your testing is inconsistent with a new pool in this short of time.