PH keeps rising - liquid chlorine?

PoolFunnSun

Active member
Jul 8, 2020
26
Newark, CA
Hi all,

I'm noticing that I need to add muriatic acid every few days because my pH rises from about 7.4 to either 7.8 or 8.0.

Searching online one of the reasons maybe because of the sodium hypochlorite (liquid chlorine) I'm using. To maintain cya/fc ratio I'm Adding about 5-8 cups daily of 10%. Recently been closer to 5-6.5 cups. CYA was slightly above 30 on the k-2006c test kit, so i rounded up to 40.

I checked TA Friday, it was 120.

Want to check in with you y'all who are more experienced to find out if this is normal and if there's anything I can do to reduce the fluctuation in pH. Maybe I'm doing something incorrectly.

Thanks!
 

setsailsoon

Gold Supporter
LifeTime Supporter
TFP Guide
Oct 25, 2015
3,386
Stuart/FL
Pool,
Ph rise is not due to liquid chlorine. Chlorine will have a net zero change on pH after it reacts. The main culprit is aeration. Lowering your TA to 80 or less should make pH easier to control. Many on here run TA down to 50.

Hope this helps.

Chris
 
  • Like
Reactions: PoolFunnSun

CrystalRiver

Well-known member
Jun 19, 2020
236
Massachusetts
pH is rising because of your high TA. TA will come down over time as you add acid (reduces both pH and TA) and aerate (increases pH but not TA).

My understanding is that liquid chlorine raises pH but only as long as the chlorine is present. When the chlorine gets consumed, either by organics or breakdown due to UV, the pH drops again. So adding 10 ppm chlorine then letting it drop back to your starting value, you have no net change in pH.

8 cups of 10% in your size pool each day is only 2.2 ppm. That's on the low side of normal. Not saying there's anything bad about it - as long as your FC is in the correct range, it's the correct amount for your pool. It's just not a lot of liquid chlorine, that it would cause any noticable change in pH.
 
  • Like
Reactions: PoolFunnSun

PoolFunnSun

Active member
Jul 8, 2020
26
Newark, CA
Thanks for the responses.

It is not a new pool, about 12-15yrs since plaster was redone.

I'll work on aeration and reducing ph after aeration until TA is lower. I'll target 80 and see how ph behaves and reduce TA if still increasing quickly.

Any suggestions for aerating?

My return jets are so old and crusty i worry they may break or crumble if I try to move them. 🤔

i do have a submersible pump that i bought to drain the pool. Maybe i put it in and use a hose connected to the pump to return water into the pool?
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
6,892
Central California
Here's some links:
 
  • Like
Reactions: PoolFunnSun

setsailsoon

Gold Supporter
LifeTime Supporter
TFP Guide
Oct 25, 2015
3,386
Stuart/FL
Pool,

Do your returns point up in the air. If so adjusting so they don't may help. If they're underwater already it won't help. The best you can do is reduce the TA and if that doesn't help you may want to try adding borates. I'd see if just getting the TA reduced works.

Chris
 
  • Like
Reactions: PoolFunnSun

PoolFunnSun

Active member
Jul 8, 2020
26
Newark, CA
Good thread, i should've search. Sorry. 😬

i hooked up my submersible pump to my garden hose. Then angled the hose in the water. Making lots of small bubbles which i understand is more ideal.

How does this aeration look? To small?

Seems decent for a last minute setup.IMG_20200803_105326.jpg
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
6,892
Central California
Looks good. But the real test will be your chemistry. Your testing will let you know if you've got enough going on there. One of those pics in that other thread is mine. They were pretty wimpy sprayers, but they did the job.
 
  • Like
Reactions: PoolFunnSun

PoolFunnSun

Active member
Jul 8, 2020
26
Newark, CA
Pool,

Do your returns point up in the air. If so adjusting so they don't may help. If they're underwater already it won't help. The best you can do is reduce the TA and if that doesn't help you may want to try adding borates. I'd see if just getting the TA reduced works.

Chris
They do not point up and are completely submerged. Seems like consensus is TA. Let's see how well my aeration works over the next few days

Looks good. But the real test will be your chemistry. Your testing will let you know if you've got enough going on there. One of those pics in that other thread is mine. They were pretty wimpy sprayers, but they did the job.
Ya tough to tell. I'll check chemistry tonight and continue running until ta gets down.

Grabbing more muriatic acid tonight to control ph during this process

Thanks all, I'll post back in a week or so with an update 🙏
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
6,892
Central California
I trust you've got that hose locked down good, especially if you're going to let it run overnight! You don't want to wake up to an empty pool, even if that would get rid of all the TA!! ;)
 
  • Like
Reactions: PoolFunnSun

JJ_Tex

Bronze Supporter
Jul 17, 2019
1,639
Prosper, TX (DFW)
Are you a former puck user? I havent seen it mentioned, but pucks are acidic. So... while liquid chlorine is neutral and doesnt cause pH to rise, you will have to add acid more often than you were when you were using acidic pucks (assuming that is what you used before switching to liquid chlorine).
 
  • Like
Reactions: PoolFunnSun

PoolFunnSun

Active member
Jul 8, 2020
26
Newark, CA
Are you a former puck user? I havent seen it mentioned, but pucks are acidic. So... while liquid chlorine is neutral and doesnt cause pH to rise, you will have to add acid more often than you were when you were using acidic pucks (assuming that is what you used before switching to liquid chlorine).
I did use chlorine tabs from Leslie's pool that caused my cya to skyrocket to 150 over one year. So the water that's in the pool now is new water that was refilled. But when I was using those pucks I never even had to touch pH expect the first time i started taking over pool care

Ohh nice. I don't have any hand rails, but i got a slide i could lay the hose on. Let's see how much progress i can make with current setup. Then I'll adjust
 

PoolFunnSun

Active member
Jul 8, 2020
26
Newark, CA
Hey all, back here to report an update that I was able to get my ta down to 80. I reduce my pH to 7.0. And with my submersible pump setup in the image above I was able to raise pH to about 0.2 each day. Once 7.6 i would add the acid. Took about 3.5 gallons of 14.5% muriatic acid to go from 120 TA TO 80 TA

I'd like to ask for assistance with determining how I can tell if I need to reduce ta even more? Should my pH only require adjustment once a week?

What's the lowest TA to safely have?

Also, I don't know if it's just in my head but I feel like now that my ta is lower my chlorine is lasting longer. Does this seem right?

Thanks!
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
14,620
Evans, Georgia
If you play with the old version of PoolMath, found below, you can input all your current levels in the far left column then fill in test amounts to the right hand column and see how it changes your CSI.
As long as you also input your gallons at the top, then go all the way down to the bottom and choose "Plaster" "bleach" and "Troublefreepools" for those options it will suggest a range for each chem level.

Play around with it :)

Maddie
 
  • Like
Reactions: PoolFunnSun