PH keeps rising - liquid chlorine?

[PoolFunnSun]

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]

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

 

[CrystalRiver]

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.

 

[YippeeSkippy]

Is this a new pool that's still curing? The pH always tends to rise during the curing process.

Maddie

 

[PoolFunnSun]

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]

Here's some links:

Let’s See Your DIY Aerators 🤗😎

Figured I had nothing better to do while I attempted the aeration method for reducing my TA. Used Mauriac Acid to reduce my Ph from 7.7 to 7.0. Now the waiting game. Here’s what I came up with using my vacuum hose, a length of PVC and a plastic iced tea bottle.

www.troublefreepool.com

Aeration - Further Reading

www.troublefreepool.com

 

[setsailsoon]

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

 

[PoolFunnSun]

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.

 

[Dirk]

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.

 

[PoolFunnSun]

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]

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!!

 

[PoolFunnSun]

Haha good point. Ya i have a bench sitting on it. I wont run overnight though. Don't trust it

 

[JJ_Tex]

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).

 

[YippeeSkippy]

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[PoolFunnSun]

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

View media item 2697

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]

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]

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

 

[mgtfp]

What's the lowest TA to safely have?

TA shouldn't be below 50. Below that, the buffering function of your TA will get too low. And since you have a plaster pool, you'll also have to watch your CSI. Lower TA means lower CSI, i.e. the water can be more corrosive to your plaster. Check your CSI with PoolMath.