Struggling to Keep pH Down (AUS)

vinezz

Member
Aug 25, 2021
5
Sydney, AU
Pool Size
36000
Surface
Fiberglass
Chlorine
Salt Water Generator
Hi all,

I am a new pool owner seeking some guidance please.
My pool is 36k L (almost 10k gallons) fibreglass with SWG and solar heating.

Last week my TA was at 165 and pH 8.1. CH at 259.
I put around 800 mL of 32% muriatic acid, hoped to bring both down.
Yesterday, I tested the water and pH still at 8.1, TA gone higher to 175, CH down significantly to 92.
CYA stayed the same at 80. FC down from 8 to 6.5 (as intented as I lowered the SWG output from 50% to 30%).
Now, the other thing was that during the week, the solar heating was on and I happened to find out that my pool water level went down to just below halfway mark of the skimmer opening, because there was a leak in the solar heating pad on the roof. Not sure if this has any impact on the water chemistry recorded above (?).

Can anyone assist me in understanding why pH did not go down and TA went up too even though muriatic acid was added last week?
Big drop in CH was also concerning. There were two days of rain last week, so perhaps it impacted the CH, but too that extent is not normal?

I had some reading and from my understanding was that pH tends to increase in SWG pool and it can be exacerbated by water feature around the return jet. Is this true?
If so, then perhaps the fact that I had my solar heating on for the week might cause the pH rise/not coming down..
My pool has 2 return jets (technically 3, but one of them in the middle is used by the Polaris cleaner), which sandwich a return jet for the solar heating, so maybe the solar return jet aerates the chlorine returned by the two return jets on its either sides causing pH rise faster?
Refer to the attached picture.
If my assumption here is correct, how can I use the solar heating while minimising/preventing pH rise and get it under control (happy with pH 7.8)?

Any advice/suggestions are very much appreciated.

Thanks
 

Attachments

  • POOL_210926_172235.jpg
    POOL_210926_172235.jpg
    147.7 KB · Views: 3
Last edited:

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2014
33,605
Texas, San Antonio/Marion, South-Central Area
Pool Size
17888
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-45 Plus
Welcome to TFP and a new swim season for those down under! :wave: It is true that aeration tends to increase pH, and salt pools seem to like a pH in the upper 7 range. Even without an SWG, pH will tend to rise every few days. Now if you had to add water due to the leak earlier, your new water's TA might have influenced your changes as well.

Biggest question everyone here will have .... how are you testing your water. In AUS I believe Clear Choice Labs is still one of the most popular and reliable test kits, comparable to the Taylor K-2006C kit? Please be sure to update your signature with all of your pool info and equipment details (see mine as an example), and include your test kit as well. We'll be happy to assist further.

 
  • Like
Reactions: vinezz

vinezz

Member
Aug 25, 2021
5
Sydney, AU
Pool Size
36000
Surface
Fiberglass
Chlorine
Salt Water Generator
Welcome to TFP and a new swim season for those down under! :wave: It is true that aeration tends to increase pH, and salt pools seem to like a pH in the upper 7 range. Even without an SWG, pH will tend to rise every few days. Now if you had to add water due to the leak earlier, your new water's TA might have influenced your changes as well.

Biggest question everyone here will have .... how are you testing your water. In AUS I believe Clear Choice Labs is still one of the most popular and reliable test kits, comparable to the Taylor K-2006C kit? Please be sure to update your signature with all of your pool info and equipment details (see mine as an example), and include your test kit as well. We'll be happy to assist further.

Hello there :) I have updated my profile with the equipments but unable to find my SWG model.
Currently, I bring my water to a pool shop nearby and have been going to the same shop for testing.
Yeah, I heard about CCL but haven't got it yet.

The last water test was based on the water sample prior me filling up the pool with some water to bring it up to halfway mark of the skimmer level, so it would not be because the tap water screwed the pool water chemistry around.

I am scratching my head but again it could be because I am very new to all of these!
I added 1.1L of 32% muriatic acid yesterday to bring the pH and TA down, and now turned off the solar heating.
 

Kenepo17

Active member
Jul 31, 2021
41
Florida
Pool Size
15000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair iChlor 30
Hello there :) I have updated my profile with the equipments but unable to find my SWG model.
Currently, I bring my water to a pool shop nearby and have been going to the same shop for testing.
Yeah, I heard about CCL but haven't got it yet.

The last water test was based on the water sample prior me filling up the pool with some water to bring it up to halfway mark of the skimmer level, so it would not be because the tap water screwed the pool water chemistry around.

I am scratching my head but again it could be because I am very new to all of these!
I added 1.1L of 32% muriatic acid yesterday to bring the pH and TA down, and now turned off the solar heating.
I own the Taylor K-2006S for saltwater since i have a SWG, i have water features like a Spa overspill, 2 pool returns and 1 fountain/bubbler. i do check my PH, TA every 2-3 days to stay on top, i do run my variable speed pump 24/7, 1800 rpms during day for 12 hrs 9am-9pm, SWG @ 15%, and at night 9pm-9am pump runs at 800 rpms in this rpm the Ichlor sense low flow and stops chlorinating. i do live in Florida USA, i tried keep my PH 7.4-7.6 and TA 70-80
 
  • Like
Reactions: vinezz

vinezz

Member
Aug 25, 2021
5
Sydney, AU
Pool Size
36000
Surface
Fiberglass
Chlorine
Salt Water Generator
I own the Taylor K-2006S for saltwater since i have a SWG, i have water features like a Spa overspill, 2 pool returns and 1 fountain/bubbler. i do check my PH, TA every 2-3 days to stay on top, i do run my variable speed pump 24/7, 1800 rpms during day for 12 hrs 9am-9pm, SWG @ 15%, and at night 9pm-9am pump runs at 800 rpms in this rpm the Ichlor sense low flow and stops chlorinating. i do live in Florida USA, i tried keep my PH 7.4-7.6 and TA 70-80
Whats CH level and CYA are you on?
 

brendio

Active member
May 18, 2020
35
Queensland, Australia
You need to do your own testing! pH and TA change with aeration and acid additions, but CH will only change slowly if water is lost and new water with different CH added. A reduction of 65% in CH without changing your water is impossible. So this points to a problem with testing. But you are not doing your own testing, so you can not troubleshoot it. Was it a different operator at the pool store doing the test wrong? Was the vial not rinsed properly? Has the machine not been calibrated? You have no way of knowing and will be second guessing yourself adding this and that based on errant results.