help, weird problem: low pH but HIGH Total alkalinity

[Brucefan1]

HI all,

this is my first post on this forum. I am real glad i stumbled across it, i hope to be on here a long time and learn some really useful info. I am new to opening and taking care of a pool. We opened our pool May 26.

My first question i have for an expert is this: what do you do if you have low pH but HIGHT Total Alkalinity? my PH is 6.9 but my TA is 190 ppm. My chlorine ppm is very low, so i know i need to add some Shock in ASAP--but should i fix the pH BEFORE i add chlorine? (since i have heard that having low pH means it will just eat up chlorine very rapidly?)

I have heard that if you try to raise your pH, then you will also end up RAISING your T.A. but on the other hand, if you try and lower TA (through muriatic acid, eg), then you will LOWER the pH...so what the heck do you do if my pH is low by my TA is high? how the heck do i take care of one without worsening the other??

i have been given conflicting answers from local pool companies, so could i please get some advice from anyone reading this tonite? i would really appreciate it (and if this question has already been asked before, sorry, but i couldn't find anythign under "Search")

--Tom

 

[duraleigh]

Hi, Tom,

Welcome to the forum....lot's of nice people here.

In a nutshell, the only way you can lower your TA is thru aeration (blowing bubbles in the pool :lol: ....lot's of 'em)

Anyway, once you start getting bubbles in the pool, your currently low pH will start to rise. When the pH get's to7.6 or so, you add muriatic acid to lower it again to 7.0 (this will lower your TA)

You simply continue the process of aeration while constantly returning your pH down to 7.0. Each step of lowering the pH will bring your TA down.

There's no other way to do it and you will need to be able to test pH and TA several times during this procedure.

More info is available here...

http://www.troublefreepools.com/sticky.php?s=5341

 

[Brucefan1]

thanks Dave.

What is your opinion (or any other expert for that matter) regarding Borax in the pool? a neighbor friend down the street said if i threw some Borax (the kind you buy at the grocery store) in the pool, it would have the effect of raising pH but keeping TA constant.

Does anyone know if this is true??

thanks,

--Tom

 

[Guest]

Borax has very little impact on TA but it will cause a slight rise so your neighbor is essentially correct. It is best to use when your TA is about where you want it but yor pH is low. In your case with low pH and high TA aeration like duraleigh suggested is your best course since you need to lower TA and that is the process--drop your pH and aerate to raise it and repeat until the TA is where you want it.

 

[Matt]

In the short term, you want the low pH. The low pH is what will let you burn off the TA. Once you get that to a level you like, then you can add borates.

6.9 is a bit low anyways... probably ok in the short term for gunite or concrete pools, but bad for vinyl lined (keep them 7.2+). You can use borax immediately to bring the pH up to a range that is safe for your pool, but don't go too high yet, because you want to burn off TA.

 

[slavapalooza]

Thank you. First time I had this problem too in 11 years as a pool owner.

 

[IceShadow]

Honestly unless your high TA is contributing to a high CSI you’re worried about, you really don’t need to worry about it. The pH is more important and aeration is the best way to make it raise unless you’re in the danger zone, but the way to lower TA is acid, which you’ll be adding to lower pH eventually anyway.

How are you chlorinating? If you’re using a SWG or liquid chlorine, your pH will rise as the TA pushes it up with CO2 offgassing from your pool, since those methods of chlorinating are pH neutral. When your pH hits 8.0, add acid to drop it to 7.6 or so. Repeat each time it gets too high. Eventually the TA will drop too, as it will go down a bit with each acid addition. It’s not something you need to force down, unless the CSI is too high due to water with high CH or something.