Process for adding Alkalinity Up

[Jacquelyn1215]

Is there a preferred way to add Alkalinity Up to the pool - either sprinkling directly onto pool surface or diluting first? (Set aside the fact that we even have Alkalinity Up... I am now seeing that baking soda is basically the same thing but this was something our start-up crew recommended we get when we first got our pool, so working our way thru this supply!)

 

[mknauss]

Just pour it into the pool. It will dissolve quickly.

You need to review your acid additions. You should not have to add baking soda and acid. Your high CH is limiting how high you can let the pH ride.

 

[pjt]

Why do you want to increase your TA? How are you testing? It's unusual for a SWG chlorinated pool to need baking soda. TA of 50 is fine. The rest of your chemistry looks good, assuming the data comes from a proper test kit. Enable CSI tracking in PoolMath.

What's the TA and CH of your fill water?

 

[Jacquelyn1215]

Thanks for the feedback. A couple of things:

• Our CH increased ~mid-May. Not sure what causes that. We'd been sitting at ~500-550 for the past year or so (or as long as I can remember, and our pool was opened in March 2022). My understanding is the only thing you can do to lower CH is to drain (at least a portion) and refill. Pool Math says to replace 31% by volume of pool's water.
• Our pH has always ran high. We've always added muriatic acid a few times a week during the summer months, less so during the off-season. pH of our fill water is <7.
• I'm seeing that the ideal level for TA is 60-80 for a plaster pool of our size with SWG which is why we were adding a bit to bring it up to 60. About a month or so ago it had dropped down to 40; we added Alk Up at that time, got it to 60 and it's dropped back down to 50. Pool Math is also flagging our TA as "outside the ideal range" so we were aiming to keep it at 60.
• We use the Taylor New K-2006 test kit and Pool Math. Hadn't enabled CSI tracking but just did that. Pool Math logs linked in my profile.
• Fill water TA is 50 and CH 70.

 

[pjt]

our pool was opened in March 2022

How did your CH get so high after only 15 months? Your fill water doesn't have that much CH. Were any calcium products added?

My understanding is the only thing you can do to lower CH is to drain (at least a portion) and refill.

That's the only practical and cost effective way to lower CH.

Pool Math says to replace 31% by volume of pool's water.

Remember, PoolMath is just a calculator. It doesn't drive decision making.

We've always added muriatic acid a few times a week during the summer months

This is driving your TA down. Let your TA and pH reach equilibrium, or you'll be chasing your tail with MA and baking soda additions. With a TA of 50, where does your pH stabilize? (I would guess somewhere in the high 7s.)

I'm seeing that the ideal level for TA is 60-80

TA of 50 is fine. That will give you pH stability and minimize pH rise.

We use the Taylor New K-2006 test kit

Put that in your signature please.

Fill water TA is 50 and CH 70

Every time you add fill water, you're adding a little TA and CH.

 

[Jacquelyn1215]

How did your CH get so high after only 15 months? Your fill water doesn't have that much CH. Were any calcium products added?

That's what we're wondering. We haven't added any calcium products. From when we opened our pool in March 2022 - July 2022 we had two different pool companies doing our maintenance. The first never shared any logs despite repeatedly telling us he would, the second shared logs but no record of anything with calcium ever being added. We have fully maintained our pool ourselves since Aug. 2022 and since then we've only added chlorine, muriatic acid (consistently), CYA (once last summer and once again this summer) and Alk Up (just recently when our TA dropped to 40).

This is driving your TA down. Let your TA and pH reach equilibrium, or you'll be chasing your tail with MA and baking soda additions. With a TA of 50, where does your pH stabilize? (I would guess somewhere in the high 7s.)

To clarify, our TA had been stable for ~ a year. It's always sat around 50-60 until this spring when it dropped to 40. That's the first time we ever added Alk Up. Our pH, on the other hand, never really stabilizes so we add MA pretty consistently. It has always been that way. If I let it go and do nothing it will get up to or possibly even over 8 within a week's time. Someone on here said at one time that that could just be how our pool is - pH runs high (I'm ad-libbing but basically something to that effect). FWIW our pool is on the east side of our house and generally has no shade so it gets a ton of intense heat the majority of the day.

TA of 50 is fine. That will give you pH stability and minimize pH rise.

Good to know, we will let the TA be, then.

 

[Mdragger88]

You didn’t ask about this but ….
your cya is a bit low for a swcg fed pool in the blazing Texas sun. Most in your area need around 80ppm cya in the peak of summer, less in the shoulder months.
Doing this will help your pool retain more of the fc your swg produces which in turn means you should be able to run it less & it should live longer In people years- as cells have a finite lifespan of around 10k hours when run @100%.

Also, which exact swg cell do you have? (Add that to your signature)

Before raising cya further you can do an
Overnight Chlorine Loss Test to be sure nothing is brewing as insurance- I always recommend this.
although your logs show that you have been maintaining adequate fc for your cya.
Turn on csi tracking in poolmath settings so you can do your best to prevent scaling with your high ch.
I also don’t see salt in your logs
You will also need that value for poolmath to accurately calculate csi for you.
Turn on salt tracking in the settings
If you don’t have a way to test salt independently of your swcg you should get the Taylor k1766. Don’t just blindly depend on the swcg. You ultimately want the swcg to be happy but you need a way to confirm your actual salt level. This will be necessary if you plan to replace/exchange water in the future anyway.
After you’re done with all your homework lol - be sure to take a well deserved dip

 

[Jacquelyn1215]

You didn’t ask about this but ….
your cya is a bit low for a swcg fed pool in the blazing Texas sun. Most in your area need around 80ppm cya in the peak of summer, less in the shoulder months.
Doing this will help your pool retain more of the fc your swg produces which in turn means you should be able to run it less & it should live longer In people years- as cells have a finite lifespan of around 10k hours when run @100%.

Also, which exact swg cell do you have? (Add that to your signature)

Okay, I did wonder a bit about CYA and thought it might be a bit low. We have the IntelliChlor® Salt Chlorine Generator (will add to signature).

Before raising cya further you can do an
Overnight Chlorine Loss Test to be sure nothing is brewing as insurance- I always recommend this.
although your logs show that you have been maintaining adequate fc for your cya.
Turn on csi tracking in poolmath settings so you can do your best to prevent scaling with your high ch.
I also don’t see salt in your logs
You will also need that value for poolmath to accurately calculate csi for you.
Turn on salt tracking in the settings
If you don’t have a way to test salt independently of your swcg you should get the Taylor k1766. Don’t just blindly depend on the swcg. You ultimately want the swcg to be happy but you need a way to confirm your actual salt level. This will be necessary if you plan to replace/exchange water in the future anyway.
After you’re done with all your homework lol - be sure to take a well deserved dip

Will try this test before adding CYA - thanks. Just turned on CSI but you're right - we only get salt readings from the SWG so just added the Taylor K1766 to the Amazon cart...

 

[proavia]

What model is your SWG?
IC40, IC60, other??

 

[Jacquelyn1215]

What model is your SWG?
IC40, IC60, other??

IC40

 

[reggiehammond]

I'm going to take a guess that your weekly pool service was still adding CalHypo shock as that's just industry standard practice to "shock" a pool weekly, even with a SWCG. Just helped a neighbor get out of his pool service and they were doing the same.

 

[Jacquelyn1215]

If you don’t have a way to test salt independently of your swcg you should get the Taylor k1766.

Thanks much for this tip. I got the Taylor K1766 test kit and interestingly that test does not align with what our SWG is telling us. Salt levels per the test kit have been 3400 the past few times, while the SWG indicated 3750 and 3800...

 

[reggiehammond]

SWCG readings are notoriously inaccurate - it's guessing salt level based on the power draw of the cell.

 

[Mdragger88]

They will almost never match exactly.
So long as the cell is happy & producing you’re good