More help with incessant pH rise

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skyeboysteve

skyeboysteve

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Feb 2, 2015
33
Grand Prairie, Texas
I know there is a lot of discussion on this matter, but haven't been able to find any tips yet (or at least understanding) that applies to the situation I find myself in.

I actually posted on here years ago with a similar question, and in the end resolved myself to using trichlor tablets (vs bleach) and draining my pool every year to get rid of CYA--yes, I'd have to drain my pool completely as I'd instantly get 30-40PPM upon refilling (probably from CYA being absorbed in the plaster); but it sure made maintenance on the pool easy, and by my records was actually cheaper than adding acid every week. I honestly could go the whole year of never adding acid or anything else but tablets.

I've recently had the pool re-plastered about 2 months ago; so I realize that's going to cause a rising pH issue... and also having simultaneously converted to SWG, (because chlorine prices have quadrupled) I understand that also contributes to raising pH through aeration.

So, I've dumped 50lbs of borate acid (about 52ppm) into the pool. (First time I've used the stuff) I'm thinking of raising that to 70ppm as some sites have suggested it is safe to do. In any case, so far it doesn't seem to help anything more than if I just slipped the skimmer $85 cash.

In 5 days time of monitoring daily my TA went from 50 to 80, while my pH went from 7 to 8.1 I was hoping by lowering my TA to 50 my pH wouldn't shoot up again like a rocket but it still rose at the same rate as usual at 60. I didn't even run my chlorinator (it produces about 16ppm of free chlorine in a 24 hour period at 25% power setting); so I was waiting for the chlorine levels to return to sanity. But I digress...

SWG hasn't run during this time... no water features, no swimming, no adding water from the hose.. only thing that breaks the surface is the polaris which loves to tie itself in knots more than usual lately.

Meanwhile my pH is like a runaway train...

Today's reading:

FC: 6.5
TC: 6.5
CC: 0
pH: 8.1
TA 80
Salt: 4400
CH: 225 (yeah slightly low but that will skyrocket on its own too and I just happily ignore it--at least it did even with the old plaster)
CYA: 50 (after fighting for a decade to limit CYA, I actually bought some for my SWG--felt like I was buying expensive weeds for my garden).
Temp: 60F
Borate: 52ppm (based on pool calculator only: not measured--yet; and those test strips seem impossibly vague anyway).

I had noticed someone had mentioned it was safe to go as low as 40 with TA if you have Borate... in any case the CSI calc thinks that's off the chart at that level, as though my pool plaster would dissolve over night... In any case it didn't stay down at 40 for more than a day when I took it down there last week.

So, (assuming anyone is bored enough to read this far); anyone have tips on how to approach this? I realize I'm in for a year of adding acid--but two gallons of muriatic acid a week is not fun... but if that's what it takes...

1) Get more Borate?
2) Take TA down to 40 again and just add acid as necessary to keep the pH low enough to keep TA from rising? I realize pH is the important factor (TA is more of a reference guide); but the reason I'm framing it this way; is to see if that is the most effecient use of acid? Just keep the pH at 7 to 7.2 so the TA can't escape 40 or 50 like it's always trying to do which in turn is launching my pH to the stars?
3) Ignore CSI for a year since I've got that fancy Borate stuff?
4) All the above?
5) Let my TA go to 90 (where it's making a bee-line for right now), and just add enough acid every night to keep my pH at 8, and hope I don't go broke in the mean time?
6) Keep my TA at 50 and add acid every night so that pH doesn't go above 7.5 so that TA doesn't go up so that pH doesn't go up, so that...?

I guess I'm just wondering what could possibly be the most efficient way to keep the pH under control, and will I ever see a day that I can stop dropping acid?
 
I would offer the following:
- TA should not change unless you add baking soda or are adding new water that has a higher TA. Do you have an autofill perhaps?
- You currently have two reasonable contributors to a climbing pH: new plaster and colder water. Remember that as water temps drop it can cause the pH to rise. It's natures way of somewhat counter-balancing each other in the winter. Don't fight a pH of 8.0, maybe even 8.1. If the APP show s a good CSI, don't fight the pH and try to make it too low.
 
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Texas Splash said:
I would offer the following:
- TA should not change unless you add baking soda or are adding new water that has a higher TA. Do you have an autofill perhaps?
- You currently have two reasonable contributors to a climbing pH: new plaster and colder water. Remember that as water temps drop it can cause the pH to rise. It's natures way of somewhat counter-balancing each other in the winter. Don't fight a pH of 8.0, maybe even 8.1. If the APP show s a good CSI, don't fight the pH and try to make it too low.
Click to expand...
Thanks for your response, @Texas Splash.

Welcome to my magical pool where TA always has gone up on its own unless I have trichlor floating around (with the old plaster). I wish I had an autofill but in any case no water (nothing at all in fact) was added to the pool during this period. I even checked with my wife to make sure she wasn't sneaking stuff into it to mess with my readings.

How high a pH is too high though even if if CSI is currently fine? TFP guidelines seem to indicate 8.0 is the top limit. During the first month after re-plaster and waiting to run the chlorinator for the first time and using trichlor while the plaster cured, my pH would spike up to 8.8 from 7.6 in a couple days while TA was at 55. Through TA would also climb in the same time period (on its own) to 65.
 
Anyone else able to help?

BTW, what is more important, CSI or being in the correct pH and TA ranges?

Six days ago my pH was 8.1 and TA was 85 giving me a CSI of -0.16

Today with pH at 8.4 and TA at 115, I have a CSI of +0.28

I just added two gallons of muriatic acid to lower my pH to 7.0 to try decreasing my TA...
 
Leebo said:
How May we ask are you testing? An increase of TA without the addition of something sounds very odd……
Click to expand...
Interesting that a rising TA is odd.... other than when I've used trichlor, TA has always gone up in my pool for the 10 years I've had it, unless I add muriatic acid... or just use trichlor floaters... which keeps pH and TA perfectly within range with no adjustments needed.

I'm testing with the "TF-Pro Salt with SmartStir-for pools with SWG" test kit.
 
TA only rises by adding something with alkalinity. In nearly all cases, that is fill water. I know you stated earlier that you are not adding any fill water, but that is the only way your TA is increasing.
 

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mknauss said:
TA only rises by adding something with alkalinity. In nearly all cases, that is fill water. I know you stated earlier that you are not adding any fill water, but that is the only way your TA is increasing.
Click to expand...
Forgot to remind in last response, this is a 2 month old plaster job... so I think that is responsible in part... but when I first got this house 10 years ago with the pool built in 1975, the last re-plaster job had been done back in 2006, and TA would always go up on it's own even then. Granted I was adding city water to keep it filled. I have also added some city water in the past week due to evaporation. Guess I should test the water supply again.
 
skyeboysteve said:
I have a digital pH tester that goes up to 14. I calibrate it routinely so that it's accurate to 0.01 on the scale.
Click to expand...
I’d recommend also testing with the drop test. I also have a digital pH meter and it doesn’t give me confidence its accurate when I test against the drop based tests.
 
The SWCG has does not significantly effect your pH. The addition of TA fill water and aeration does.

Trichlor is adding acid continuously. Along with a build of CYA
 
mknauss said:
The SWCG has does not significantly effect your pH. The addition of TA fill water and aeration does.

Trichlor is adding acid continuously. Along with a build of CYA
Click to expand...
I understand that... I have virtually no aeration other than from the SWG and polaris sweeper... and yes, understand that the reason trichlor kept my pool in check was because of the acid it provides... but just curious if there's a way to keep from having to add murriatic acid for the rest of my life, besides closing the pool and / or moving?

Thanks for your time btw.
 
As your fill water adds alkalinity, you will always need to add acid. Borates do not stop that. They just increase the time BETWEEN acid additions, not the amount of acid used.

I find it not a big deal to add a bit of acid once or twice a week. You can install a pump/tank dispensing system for acid if you wish. You still have to test the pH and TA often and adjust the systems run time to how much acid is needed to add.
 
skyeboysteve said:
I understand that... I have virtually no aeration other than from the SWG and polaris sweeper... and yes, understand that the reason trichlor kept my pool in check was because of the acid it provides... but just curious if there's a way to keep from having to add murriatic acid for the rest of my life, besides closing the pool and / or moving?

Thanks for your time btw.
Click to expand...
One thing that will help is if you only dose it down to pH 7.6-7.8. The farther you drive it down from where it naturally wants to be, the faster is rises to its happy place. You might try seeing if you can just knock it down to 7.9 or 8 once or twice a week.
 
Bperry said:
One thing that will help is if you only dose it down to pH 7.6-7.8. The farther you drive it down from where it naturally wants to be, the faster is rises to its happy place. You might try seeing if you can just knock it down to 7.9 or 8 once or twice a week.
Click to expand...
Okay, I'll try not knocking it down so much... but I'm starting to feel like I made a bad financial decision switching to SWG

Before:
$105/year on 50lbs of Trichlor (that's gone up recently to $400)
$150/year of city water to refill the pool to get rid of the CYA (which would often hit 100ppm in one year)

Now: (forecast)
Currently averaging in the cooler months: 1 gallon Muriatic Acid per week, will cost me $850 per year in acid alone.
(not counting the $1600 I spent on the SWG, the $120 on salt, the $90 Borate etc).

So... even with Chlorine being quadriple the price it used to be and the cost of replacing 20,000 gallons every year with "fresh" water... I would have been better off financially sticking to Trichlor... not to mention it was a very hands off method where I hardly had to do anything but keep the floaters full. My chemistry was almost always near perfect. Only needed to shock the pool once per year; free chlorine levels were easily controlled, and everything else stayed nicely in their correct ranges too--thanks of course to what this site has taught me btw... so I'll always be thankful to the knowledge and wisdom I've learned from this forum and the guides in general from TFP.
 
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