High PH, liquid chlorine, and salt system relationships/questions?

[rayc82]

Hi friends,

I started managing my own pool chemicals recently after firing a very poor pool service company who didn’t seem to be doing a good job. My pool specs:

-2017 built 20k gallon gunite and pebble
-chlorine and UV sanitizer
-also includes a spa where part of pool design returns some water there and then from spa is a spillover into main pool

After taking over chemicals myself, I initially noticed that I had a very high PH problem (use 1-2gallon or Muriatic acid every week) to maintain it within range. Alkalinity is about 100. According to a Leslie’s water test the only thing way off the charts is TDS 4700 (which I know I need to eventually fix)

I do not have any water features on, but my pool design does return some of the pool water into a spa which causes aeration, and then from spa spills over into the pool (causing more aeration on the drop). I understand aeration does increase PH. I have since reduced my VS pool pump speeds which reduced the aggressiveness of the aeration caused by the spa’s pool return and spillover drop, and it helped (maybe it’s 1 gallon acid or so a week now)

But I understand this is still an abnormally excessive use of acid.

This brings me to my questions/scenario:

I just had a very reputable and different local pool service company (I.e. also expensive) come out to provide an estimate to convert my system to salt. I asked advice about the PH problem and the pool guy told me my pool design with the spillover shouldn’t cause that significant of a PH issue, referencing other similar pools his company manages that don’t take as much acid as mine. He said it could be me using liquid chlorine which has high PH and can cause it.

Question:
1) He recommended using liquid chlorine to only bring chlorine to acceptable levels and acid to reduce PH within range, then once balanced, just use chlorine tablets to maintain chlorine since tablets have low PH impact. Is this true and will it help my seemingly runaway high PH problem significantly?

2) side note: he also mentioned if I install a salt system which the original reason for the service call— the downside for salt is often we are fighting higher PH as well (I forget the specific reasons why). Is this true and will it exacerbate my issue? He said there are some fancy options I can install with the salt system like a detector that has a chemical tub inside that needs to be refilled regularly that can inject acid if it detects too high PH. My friends with salt systems don’t seem to have PH issues like mine, and adding some type of PH injection system to me adds complexity and cost I may not want.


Would love all your thoughts to a newbie. Thanks so much, this forum is fantastic, I’ve learned a ton!

 

[HermanTX]

Welcome to TFP.
Please read up on Pool Care Basics and the section on recommended levels
It would be best if you can provide all your test values, so we have a complete picture.
pH
FC
CC
CH
TA
CYA
Water Temperature

It is uncommon to be using a gallon of MA a week for a 20k gal pool. Post a photo of your pool and specifically of the spa spillover. Maybe others have some thoughts on that after reviewing the photos.

You may want to read up on TA and pH Relationship. PH TA Relationship - Further Reading
Your TA of 100ppm is not too high (assuming that the Leslie's test is close - we don't have a lot of faith in pool store testing) so please consider purchasing your own test kit.

1) He recommended using liquid chlorine to only bring chlorine to acceptable levels and acid to reduce PH within range, then once balanced, just use chlorine tablets to maintain chlorine since tablets have low PH impact. Is this true and will it help my seemingly runaway high PH problem significantly?

Liquid Chlorine (LC) is not the cause for high pH. While it is slightly caustic and can temporarily raise pH it is not the main cause. I used LC for years in a slightly smaller pool with no impact to pH. Although I keep my TA in the 60-70 range which helps resist pH rise. I also have a spillover spa into the pool that is constant.

IT would be good to know which chlorine tablets was recommended. One type is Trichlor which is a mixture of Chlorine and CYA - so these actually help reduce pH, but the downside is that it adds significant CYA which is not good for the long term. Another type is Cal-Hypo which adds Chlorine and Calcium. Increasing calcium is also not good for the long term.
In general, the TFP methodology prefers either SWCG (salt systems) or LC. Chlorine tablets can be used for specific situations and for a limited time.

2) side note: he also mentioned if I install a salt system which the original reason for the service call— the downside for salt is often we are fighting higher PH as well (I forget the specific reasons why). Is this true and will it exacerbate my issue?

A saltwater chlorine generator (SWCG) only produces chlorine. Therefore MA is needed to control any rise in pH. It really is no different then LC which I presume you are currently using as LC only adds Chlorine and Salt to the pool water.

According to a Leslie’s water test the only thing way off the charts is TDS 4700 (which I know I need to eventually fix)

The TDS is mainly salt and that is from the use of LC. It is also preferred that you do your own testing with one of the recommended test kits Test Kits Compared

He said there are some fancy options I can install with the salt system like a detector that has a chemical tub inside that needs to be refilled regularly that can inject acid if it detects too high PH. My friends with salt systems don’t seem to have PH issues like mine, and adding some type of PH injection system to me adds complexity and cost I may not want.

There several devices on the market that can directly add MA to your pool water. It can add complexity and there is a mixture of reviews on this forum regarding the pros and cons.

 

[Dirk]

Herman is so polite. I'll play bad cop, because I'm in a mood!!

Firstly, welcome to TFP Ray. Glad you found us. You are in the right place. We can have you straightened out in short order, but before we can do that, you have to help us help you. We need a proper signature filled out, that describes your pool and all your equipment. Use mine or Herman's as good examples of what we're after. Don't skimp on the details, even if you think they don't apply to this particular issue. Just fill it in here: https://www.troublefreepool.com/account/signature

Second: you need an accurate test kit, and you need it right now. Herman gave you the link for more info. This isn't really optional. You CANNOT take care of your own pool properly without one of the two recommended kits. Every one of us here at TFP has one or the other. And we're going to be hard pressed to give you meaningful advice without a reliable set of test results. Most of us here won't even try. NOT from Leslie's, but from one of the kits. Herman showed you what we're expecting, the list of test results, vertical like that, in that order.

Third: STOP GOING TO LESLIE'S for testing. I'm not kidding. You can go there to buy chlorine, or acid, but NOTHING ELSE! It's a long-winded explanation why. Others might care to explain. Short version: using a pool store for testing, and/or allowing them to recommend pool chemicals is a recipe for failure. Not to mention a needless expense. You don't need most of what they will try to sell you. And more often than not their test results are not accurate. And they are never going to be consistent from day to day, or store to store.

Fourth: Forget everything your new "pool guy" told you about tabs. Again, Herman was being kind. Tabs are the devil, and are NOT a part of a viable, long term, low-maintenance pool-care regime. They just aren't. Not to mention most of what he claimed about them is not true.

Fifth: Please look on the jugs of the acid you are using to determine the percent of acid. It'll likely be around 14%, or 31%. If you've been buying 14%, that's half the problem solved. By that I mean you may not be pouring as much acid into your pool as you think you are. If you're using 1 gallon a week of 31%, then that's something else again.

Others here can share more on the advantages of using an SWG. You definitely want to go that route. I don't have the energy to write out the spiel tonight, but you will absolutely not be sorry if you end up with one. Long term costs of chlorinating with an SWG are not far off from doing the same with liquid chlorine. Again, tabs are NOT an option. We would need your signature filled in to best advise you about which SWG brand(s) and models to consider.

So...
- fill in your siggie,
- order your kit,
- post your test results when the kit arrives.

Sincerely,
Grumpy Dirk

Ps. When you do your first suite of tests, also do pH, TA and CH on the water with which you fill your pool. Based on your description of your pool and the pH issue, your fill water probably is part of the dealio.

 

[rayc82]

Herman and Dirk, you both are being way too nice and I sincerely appreciate you taking time to provide all this information. Sorry for being a frustrating newbie who doesn’t provide the basics of what it takes for you all to help me.

I will take what your recommendations and will be back with better data. (To answer one of your questions, Currently using 14.5 acid, but yes still abnormal, and will come back with more about the pool).

Thanks for even initially trying to ballpark address my issues. I felt a bit skeptical on what the pool guy was telling me, so I appreciate your sanity check.

I’ll be back!

 

[Dirk]

I think I've heard of others here using a gallon of acid a week. I think my pool guy used to pour in that much. And with 14% acid, that might not actually be abnormal. I bet @mknauss would know. Marty, is a gallon of 14% muriatic a week in a 5-year-old 20K pebble pool all that abnormal?

I know my pool is up there. My acid dispensing is automated, so I don't actually know exactly how much I use. Let's see, I dilute 31% in half, and probably fill my hopper every couple of months or so. It holds four gallons, so that might be a half a gallon a week. And my pool is a little over half the size of yours. We're not that far apart, at all.

I can tell you this, there seems to be a factor of diminishing return. This is a little vague, but it goes something like this. Back when I was fighting with my pH and TA numbers, I kept turning up my acid dispensing. I started to notice that it was not linear. The lower I tried to get my pH, the more acid I used, but it was logarithmic. One pH point lower might be X amount of acid, but two points lower wasn't 2X, it was more like 3X. When I stopped trying to reach some arbitrary lower pH, and let the pool find its own "happy place," I started using way less acid. Hope that made sense.

You may be a newbie, but you're not a frustrating one, at all! There's a learning curve. We all went through it. Now if you want to hear about a frustrating newbie, just ask Marty! He was my mentor, and boy, did I put him through the wringer! He was so patient. It just took me a while to "get it," because of the way I happen to learn things. What took me the longest to learn was to trust the advice I was getting from him. Our experts and guides all teach the same MO here. There is no debating going on, there are not multiple disciplines. Just the one. And it works. Herman might "encourage" you to get your test kit. I may flat out "demand" that you do. But it's really the same advice. We are both telling you you're gonna need that kit! You'll find the same to be true of the other advice you'll get here. More than one "helper" will chime in, but we are all practicing and teaching the same specific method of pool care. And if we stray, our Mods jump in and straighten everybody out. It's a very cool system they got here.

You'll have the most success here if you follow the advice carefully, answer any questions you're asked thoroughly, and just generally give the site and the TFP method a real shot. Don't mix and match advice from multiple sources, like some from the pool store, some from here, some from a neighbor. That won't work. Pick one and go with it. (You know, this one!)

You'll get it. And soon enough you'lll be helping "newbies" yourself, whether they're frustrating or not.

 

[mknauss]

What is the TA of the fill water and how much do you add?

 

[Dirk]

What is the TA of the fill water and how much do you add?

He's working on getting his test kit and then posting all the numbers... might be a bit before he can answer that. I've asked him to post a full suite for the pool, and pH, TA and CH for his fill water.

 

[HermanTX]

I will take what your recommendations and will be back with better data. (To answer one of your questions, Currently using 14.5 acid, but yes still abnormal, and will come back with more about the pool).

@Dirk made an important point that cannot be overlooked - you have to follow one process and not multiple sources such as from a pool store & a neighbor. The TFP methodology has been used and endorsed by thousands (hundreds of thousands) of users which has kept pools crystal clear, algae free and maintained at low cost (minimal use of chemicals).

Also, since your current MA is 14.5%, it most likely NOT "abnormal" usage for your 20k gal pool. Based on our PoolMath app - to lower your pH by 0.2 using 14.5% MA requires 25 oz. To lower the pH by 0.2 using 31.45% MA requires just 13 oz. So, you may perceive you are using a lot of MA, however you can cut that usage in half by using a higher strength MA.

Your action list:
Buy one of the recommended test kits,
test both your pool water and your tap water (used to top up the pool),
post those results,
identify what chemicals you are currently using (LC, MA, other),
post photo of your pool & equipment pad and
Create Your Signature to help us understand what your is current setup.

 

[Dirk]

@Dirk made an important point that cannot be overlooked - you have to follow one process and not multiple sources such as from a pool store & a neighbor. The TFP methodology has been used and endorsed by thousands (hundreds of thousands) of users which has kept pools crystal clear, algae free and maintained at low cost (minimal use of chemicals).

Also, since your current MA is 14.5%, it most likely NOT "abnormal" usage for your 20k gal pool. Based on our PoolMath app - to lower your pH by 0.2 using 14.5% MA requires 25 oz. To lower the pH by 0.2 using 31.45% MA requires just 13 oz. So, you may perceive you are using a lot of MA, however you can cut that usage in half by using a higher strength MA.

Your action list:
Buy one of the recommended test kits,
test both your pool water and your tap water (used to top up the pool),
post those results,
identify what chemicals you are currently using (LC, MA, other),
post photo of your pool & equipment pad and
Create Your Signature to help us understand what your is current setup.

Ray, betcha didn't think asking a question on an Internet forum would end up being so much work!! But it'll be worth it.

Just to expound on Herman's To Do list... you'll do a full suite of tests on your pool water and post the results back here in this thread. But we don't need you to do a full set of tests on your fill water. You can if you want, it'll be good practice as you're getting used to the kit. But we only really need pH, TA and CH for the fill water. Either way, don't test for CYA in your fill water, there won't be any and you don't want to use up that test for nothing. Your fill water might have some FC (chlorine), but we don't really need to know that number. This will all make more sense when you start using the kit, and when you start getting the advice about all the numbers. You'll get a hang of how your fill water chemistry, especially CH and TA, drives your pool's chemistry.

And to be extra clear: Herman points out that by "tap water" he means the water you use to keep your pool full. If you have a water softener, don't test the water coming out of a faucet in your house, you'd have to test the water coming out of a hose bib outside (unless you're filling your pool with soft water, which some of us do, but more on that later).

 

[Dirk]

I know we're loading you up pretty good. Just go slow, ask lots of questions, no problem. That said, you'll eventually want to start using TFP's app: Pool Math. We can walk you through that, too. But if you're bored, you might load that on your phone, just to be ready to use it when you want to. I think it's still free to load up, and useful as is, but then you in-app purchase a subscription when you want to start using all it's other amazing features. It's only a few bucks a year, and worth ten times that. You use it to record your test kit results, and when you plug in the numbers it tells you what to dose. It really is indispensable. That's its primary function, but it's got some other great tools and chemical calculators to fool with as well.