pH: how much is too much muriatic acid?

[Jacquelyn1215]

Brand new pool completed in March. PH has been an ongoing issue in that it's higher than it should be. I know that's not uncommon in new pools but trying to understand the best course of action, and how much muriatic acid we should be adding in an effort to bring it down. Here are our #s from the past month from our pool service company:

Aug. 19:
10 ppm total chlorine
8.0 ppm pH
150 ppm total alkalinity
30 ppm cyanuric acid

Aug. 12:
3 ppm total chlorine
8.0 ppm pH
100 ppm total alkalinity
0 ppm cyanuric acid
0 ppm total bromine

Aug. 5:
5 ppm total chlorine
8.0 ppm pH
120 ppm total alkalinity
0 ppm cyanuric acid

July 30:
10 ppm total chlorine
8.0 ppm pH
90 ppm total alkalinity
0 ppm cyanuric acid

July 22:
20 PSI filter psi
3400 ppm salt
0 ppm total chlorine
8.2 ppm pH
120 ppm total alkalinity

As you can see, we've been consistently sitting right around 8 which is more or less where it's been since March. The guys who maintain our pool pretty regularly add muriatic acid, but I'm wondering if we should also be adding some throughout the week (they come 1x/wk on Fridays). (Side note: we do plan to take over our own maintenance once we get more comfortable with the test kit we bought - plus we've been gone for the past month so needed someone here to maintain.)

We are also now seeing some major "blotchiness" throughout our pool; you can see it most closely on this pic of the sundeck but it is throughout the entire pool. I fear this is calcium scaling and potentially related to the high pH? But again, super confused because I've frequently heard that pH runs high for new pools for quite some time.

Appreciate any advice!

 

[Texas Splash]

Once a pool is initially cured and past its first 30 days of fill (which yours obviously is), it is very important t manage the pH and TA in the summer as those items along with the calcium level (CH) and warmer water determine how likely your pool is to scale. We can't validate the accuracy of those test results unless they are from a TF-100 or Taylor K-2006C test kit, but the TA can easily be lowered to about 50-60 ppm which should help slow the rise of pH. To do that you need one of those test kits and the ability ot add acid yourself throughout the week. Weekly pool services do a "dump & run" and often times results in neglect to the water. With muriatic acid, lower the pH to about 7.2. Once it rises to 8.0, lower it again to 7.2. Each time you do that to the pH it will slowly lower the TA. Remember that as water is added to the pool it can easily increase the pH and/o TA, so this is a constant issue during the hot TX summer.

 

[PoolGate]

I still, at 6 seasons, add almost a gallon of acid per week in-season.

 

[Dirk]

Without knowing what they're using to test pH, who knows what your real number is. Maybe their test, like mine, only goes up to 8!!

The once-a-week crew in charge of maintaining my pool before I owned it destroyed the plaster, letting scaling get out of control. Since I took over my pool after replacing the finish, no scaling! And I've been doing so longer than they did, so I know TFP works, and that what I'm doing works.

I use acid-injection automation that maintains my pH every hour! Once a week is not nearly enough for a new pool. And I have some direct evidence that shows maintaining the correct pH as often as possible makes a huge difference in scaling. At least in my pool.

Do yourself and your pool a huge favor: fire you pool guys and take it over yourself. Like, yesterday. You are already seeing the effects of what improper water maintenance can do, is doing. What are you waiting for? More scaling?! (Sorry, a little tough love there.) Buy a kit today, and start immediately testing your pH yourself when it shows up, then every day. Dose your water with acid to bring your pH into range, every day. If after some time you determine you can test and dose every other day, or every third, whatever, then do so. But until you know what your pool needs, and how often, you might be ruining it by assuming some pool guy does.

 

[Dirk]

PS. If you want to hear more about the acid automation I use, I'd be happy to share. With your Pentair IntelliChlor, you're already all set up to add the same one I have. If you're the tiniest bit handy, it's a DIY installation.

 

[Dirk]

PPS. If you really have no CYA in your pool, then your crew really doesn't know what they are doing. We can help you straighten all that out once you get the right test kit.

 

[gingrbredman]

If you really have no CYA in your pool, then your crew really doesn't know what they are doing

That was my thought exactly!

On top of that, for a weekly service to let the pool get down to 0 chlorine, then what are they even doing at all? Your signature shows a salt water chlorine generator, so something isn't right there at all.

July 22:
20 PSI filter psi
3400 ppm salt
0 ppm total chlorine

There is an issue with the pool chemistry, what exactly that is we can't be sure of until you can get a good set of test results, but there is also a big issue with that weekly service for sure.

 

[IceShadow]

"Too much" would be enough to bring the pH down below 7.0 on any given addition.

There's really no limit to how much would be put in over a longer period of time like a week or two, so long as each addition doesn't lower the pH below 7.0.

 

[Dirk]

That was my thought exactly!

On top of that, for a weekly service to let the pool get down to 0 chlorine, then what are they even doing at all? Your signature shows a salt water chlorine generator, so something isn't right there at all.


There is an issue with the pool chemistry, what exactly that is we can't be sure of until you can get a good set of test results, but there is also a big issue with that weekly service for sure.

Yah, I saw that FC-zero and it brought back all the bad memories of my pool guy. The water was always irritating for a few days after he left. I had regular bouts of greenish walls, probably because they let my CYA get out of control, but didn't know anything about CYA. They couldn't figure out at which speed to run my two-speed pump. I had them install an SWG, and for months after that the FC would often be zero!? Just numbskulls. It sounds like @Jacquelyn1215 is in the same boat. Best thing I ever did for my pool was firing them. In my first week on my own I was doing a better job.

 

[Jacquelyn1215]

PS. If you want to hear more about the acid automation I use, I'd be happy to share. With your Pentair IntelliChlor, you're already all set up to add the same one I have. If you're the tiniest bit handy, it's a DIY installation.

I am *not* the tiniest bit handy but I am intrigued; tell me more.

 

[Jacquelyn1215]

Thanks, all, for the helpful advice/insight. We have purchased the Taylor K-2006 Test Kit and have just started to get acclimated. We had a leak issue for a bit after we filled the pool (which obviously caused pH issues b/c we had to keep filling) which has since been resolved, thank god, and then we were gone for a good chunk of time last month and needed someone here to maintain the pool - hence having the service company "maintain" it... Our intent has always been to take this on ourselves and the time has clearly come. I'm sure there will be more questions!

 

[Dirk]

I am *not* the tiniest bit handy but I am intrigued; tell me more.

Pentair's IntellipH (IpH) is their acid injection automation system. It is a companion to their IntelliChlor (IC), which you already have. The IpH would plug into the IC's power supply, where your IC is now plugged in, and then your IC's cord plugs into the IpH's controller. You mount the IpH controller to the wall, find a good spot for the IpH tank, and then install the IpH injector into one of your pipes on your equipment pad. That last part is just drilling a hole in a pipe and using a screw driver to install the injector. That's it.

You fill the tank with acid, and set the IpH controller, and then that controller operates and coordinates both itself the your IC.

If you don't have a Pentair pool automation controller (you don't have one in your signature), then you can now only set your IC's output % to a few increments: 0, 2, 4, 6, 8, 10, 20, 40, 60, 80 and 100. WIth the IpH controller in the mix, you can control both your acid additions and your chlorine additions in 1% increments, from 0 to 100.

I now rarely handle chemicals, except to fill my IpH tank a few times a year. The rest of the time, my IpH and my IC are doing all the work, the IpH adjusts pH every hour, and the IC does its thing every 5 minutes, so my pH and FC are always very stable. You still have to test the water regularly, and occasionally adjust the IpH and IC to account for the seasons, but it's all pretty simple once you get it down (which, of course, we'll help you figure out).

There are some caveats I'll go over if you're interested. But that's the gist of it. If you someday add Pentair pool automation, then the IC will be controlled by that. But they all work together.

Or once you take over your pool, you could run everything as is, and get a feel for how running your existing IC works, and how manually adding acid works, and then later determine how much automation you're up for.

 

[Dirk]

Congrat's on the purchase of your kit. Yes, there's a learning curve to taking over your pool, but you, and it, are going to be way better off in short order. And we're going to help you every step of the way.

If me, and 330,248 of my pals can do it, so can you. That's the current number of TFP Members that started out with their pools pretty much just like you! Most of us never had a pool before, and the rest of us struggled with pool guys or pool stores for months, or years, but never quite got that perfect, trouble free pool. And then we stumbled onto this site, bought our kit, followed along, and are now all very happy with our TFP pools. Just like you'll be!

 

[Jacquelyn1215]

Congrat's on the purchase of your kit. Yes, there's a learning curve to taking over your pool, but you, and it, are going to be way better off in short order. And we're going to help you every step of the way.

If me, and 330,248 of my pals can do it, so can you. That's the current number of TFP Members that started out with their pools pretty much just like you! Most of us never had a pool before, and the rest of us struggled with pool guys or pool stores for months, or years, but never quite got that perfect, trouble free pool. And then we stumbled onto this site, bought our kit, followed along, and are now all very happy with our TFP pools. Just like you'll be!

Super! Love the support in this forum.

 

[Jacquelyn1215]

Okay, we did our test this a.m. and entered everything into the Pool Math app. Here's what we've got:


It really does look like there is no CYA. When we did the test I added the water to the smaller tube per the directions, and while the black dot at the bottom of the tube gets foggy, it never really disappears; it's still visible even when we fill it all the way to the top. We have dry stabilizer (which Pool Math recommends adding), and my question is - can we also add that since we've added the recommended muriatic acid and calcium chloride?

 

[IceShadow]

Careful with the pH test. It will show artificially high while the FC is over 10.

You can add some CYA. Add 10ppm to start. Let it mix for a few days before testing again.

 

[Dirk]

Yes, do your CYA additions incrementally, sort of sneaking up on your target level. Wait several days between each addition, as it can take a while to mix in well and register on the test. What you want to avoid is going over your target amount, by adding too much too quickly, as you can't reduce your CYA without draining water (or waiting months for it to come down on its own).

 

[Jacquelyn1215]

Careful with the pH test. It will show artificially high while the FC is over 10.

You can add some CYA. Add 10ppm to start. Let it mix for a few days before testing again.

Maybe you can help me understand this. Our pool company added 3 lbs stabilizer on 8/12. Their last CYA reading on 8/19 was 30ppm. But when we tested this a.m., we are seeing 0. Maybe we are not doing the test properly? When we follow the instructions for the CYA test, it says to keep adding the reagent until the water becomes foggy and the black dot at the bottom of the sample tube is no longer visible. That never really happens. The water gets a bit cloudy but the black dot never really goes away. So my two concerns are, 1) are we doing the test correctly/are we missing something, 2) if they added 3 lbs stabilizer on 8/12, my understanding was that CYA never really goes away once added. Is that right? So why would it go back down to 0?

 

[PoolGate]

Maybe you can help me understand this. Our pool company added 3 lbs stabilizer on 8/12. Their last CYA reading on 8/19 was 30ppm. But when we tested this a.m., we are seeing 0. Maybe we are not doing the test properly? When we follow the instructions for the CYA test, it says to keep adding the reagent until the water becomes foggy and the black dot at the bottom of the sample tube is no longer visible. That never really happens. The water gets a bit cloudy but the black dot never really goes away. So my two concerns are, 1) are we doing the test correctly/are we missing something, 2) if they added 3 lbs stabilizer on 8/12, my understanding was that CYA never really goes away once added. Is that right? So why would it go back down to 0?

Hmm.... The CYA test is 50% pool water and 50% CYA reagent. Mix, let sit a minute, shake, then slowly pour into the measuring tube. How are you doing it?

 

[mknauss]

3 lbs if CYA stabilizer in your pool is 24 ppm. If the water in the test was cloudy but you could barely make out the dot, that sounds about right.