PH problem

[Poolidiot]

I have tried to search for this, but did not find anything that was helpful (who knows, maybe I am a searchidiot also ). But I can not keep my PH down. I will test and it will be 8 or 8.2, I will add MA and test and it will be down to 7.2. But then in a matter of days (4-5) it is back to 8-8.2. I do not have any fountains or any other type of water feature. Swimmers are myself (not a splasher), my wife ( definantly NOT a splasher), my 6 year old son (some what of a small splasher) and my 2 year old daughter(not a splasher). Anyone have any suggestions? My numbers are:
FC - 4
CC - 0
TC - 4
PH - 8
TA - 120
CYA - 35

If it is a common easy answer, please fill free to just say , you IDIOT, this is what the problem is

 

[frustratedpoolmom]

That is unusual. You should following the process for lowering TA in Pool school, bringing it down to 70-90 ppm and see if that helps. Have you been noticing your TA coming down when you lower the PH? What kind of change in TA have you seen over time?

Is your return pointed up, breaking the surface of the water? That counts as aeration. Also, is it possible you have air getting into your pump lines? The air bubbles returning to the pool are a sign, do you have any of that that you can see? there might be an air bubble that is visible in the clear cap attached to your pump?

 

[Poolidiot]

That is unusual. You should following the process for lowering TA in Pool school, bringing it down to 70-90 ppm and see if that helps. Have you been noticing your TA coming down when you lower the PH? What kind of change in TA have you seen over time?

I have not seen any change in my TA. It has been at 120 all summer.

Is your return pointed up, breaking the surface of the water? That counts as aeration. Also, is it possible you have air getting into your pump lines? The air bubbles returning to the pool are a sign, do you have any of that that you can see? there might be an air bubble that is visible in the clear cap attached to your pump?

The return is pointed down (with a slight angle to get the circulation around the pool.So it does not break the water surface at all). I know of no air getting into the lines or any air bubbles that I can see.

 

[Poolidiot]

You should following the process for lowering TA in Pool school, bringing it down to 70-90 ppm and see if that helps.

I have started this process as we speak, will see what affect it has.

 

[Poolidiot]

You should following the process for lowering TA in Pool school, bringing it down to 70-90 ppm and see if that helps.

I have started this process as we speak, will see what affect it has.

UPDATED test #'s
Ok, I added 46oz of MA and pointed the jet up. 30 minutes after doing this I tested and here are my numbers:

PH - 7.2
TA - 100 ( does this look right, would TA come down 20 with 46oz of MA?)

I will recheck in about 2 hours

 

[jsaiken]

As a curious newb what does "water bubbles" have to do with it?

 

[frustratedpoolmom]

MA lowers both the PH and TA, so yes, you should see it come down when you add the MA. That's why when you said your TA has been stable prior to this it doesn't sound right.

Are you adding any other products to your pool that might contain Baking Soda or soda ash or Borax?

 

[frustratedpoolmom]

As a curious newb what does "water bubbles" have to do with it?

Air bubbles in the water, breaking the surface, is aeration, which causes ph to rise. You can read more about it in detail in the Lowering Total Alkalinity article in pool school. That's why pools with sources of aeration like a SWG or a spa or waterfall experience rising ph and its recommended to run with a lower TA to keep it from drifting up. Others (myself included) are able to run their TA above 110 with no PH issues. Every pool has it's own unique situations. So if he's got air in his lines causing aeration, that could explain why his PH keeps going up. But what's wierd is the TA is stable, even tho he's been adding Muratic Acid, which normally lowers both.

Hope this helps.

 

[Poolidiot]

MA lowers both the PH and TA, so yes, you should see it come down when you add the MA. That's why when you said your TA has been stable prior to this it doesn't sound right.

I agree that MA will bring TA, I just didnt think 46oz would bring it down 20ppm

Are you adding any other products to your pool that might contain Baking Soda or soda ash or Borax?

This year , all I have put in the pool is bleach and some CYA a month or so ago, other then those I have not put anything in.

Well it had been 2 hours , so I checked the numbers again:

PH - 7.2
TA - 100

 

[Poolidiot]

Well numbers are still the same. No one else has any insight on what the problem might be?

 

[chem geek]

Starting with a pH of 8.0 and a TA of 120 and CYA of 35, adding 46 ounces of Muriatic Acid would result in a pH of 7.33 and a TA of 110. This is within the measurement error of your test kit since you said you had a pH of 7.2 and a TA of 100. If you aerate sufficiently, you should see the pH rise with no change in TA. Then additional acid will lower both the pH and TA. If you lower the pH even more closer to 7.0, the aeration will make the pH rise even faster (but I assume your test kit measures pH down to 6.8 so that you'll know you didn't go too far).

As for why you haven't seen a drop in TA over time, I suspect that it is increasing from the combination of evaporation followed by refill from fill water that has moderate-to-high TA. Even my pool slowly rises in TA over the season since my fill water is 80 ppm TA. Any TA (or CH, etc.) in the fill water is incrementally added to the pool when there is evaporation.

Richard

 

[Poolidiot]

Thanks chem geek, but what about my PH that will not stay down?

 

[chem geek]

I don't know. The TA is higher than one would want for stable pH, but your pH rise is quite fast especially since you don't have any aeration features. If your pool was plaster, then new plaster curing would raise the pH, but your sig says it's above ground which I presume is vinyl.

If there was a way to put a cover on your pool and if that cuts down the pH rise, then that would indicate the pH rise was due to carbon dioxide outgassing, though we still wouldn't know why it was so fast. If you didn't use the pool for a number of days and if the pH rise was less, then it could just be using the pool that is doing it. Aeration doesn't have to be bubbles -- just disturbing the air-water surface boundary will make mixing and outgassing faster.

What are you using as your source of chlorine? Perhaps the particular brand of bleach you are using has a lot of lye in it. Clorox Regular has the least with a pH of 11.4 while most off-brand Ultra bleaches have a pH of 12.5 but even that would only cause an additional 0.2 per month rise in pH if chlorine use was 2 ppm FC per day.

Richard

 

[Poolidiot]

your sig says it's above ground which I presume is vinyl.

Yes, ABG vinyl

If you didn't use the pool for a number of days and if the pH rise was less, then it could just be using the pool that is doing it.

Well, in a few days I can test this therory, I will be leaving for a couple weeks for vacation, So I can check it before I leave then check it 2 1/2 weeks later when I get back

What are you using as your source of chlorine? Perhaps the particular brand of bleach you are using has a lot of lye in it. Clorox Regular has the least with a pH of 11.4 while most off-brand Ultra bleaches have a pH of 12.5 but even that would only cause an additional 0.2 per month rise in pH if chlorine use was 2 ppm FC per day.

I use Albertsons off brand called Always Save Ultra bleach , sodium hypochlorite 6%, other ingredients 94%, contains no phosphorus