pH going up a normal amount?

[jesse-99]

Since I'm colorblind, doing the pH test in the TF-100-PRO test kit is hard for me. So I bought an $80 digital pH test by the recommendation of someone on this site. I'm finding that my pH is going up regularly. On early Monday morning, pH was 8.3, and I added about 45 oz. (of 31.45% muriatic acid) based on Pool Math to hit a target of 7.6. Checked it today, it was 8.2. So Pool Math told me to add 60 oz of 31.45% muriatic acid to hit a 7.4 target or so, so I added the 60 oz worth of MA. My pool is between 32,000 and 34,000 gallons. Is this fairly normal that pH might be hard to keep down and am I doing the right thing based on the pH readings I'm getting by just adding the MA as often as I need? it's been really hot and sunny for 10 days straight now.

I -think- my TA is around 90 to 120, but again, my color blindness makes doing a TA test really hard to do for my eyes. I mention this cause i think having a higher TA make drift of pH less likely? (or is it vice versa).


(Everything else looks really good. FC, CYA, etc. and water is crystal clear.)

 

[PoolGate]

Yep pH regularly goes up especially with a plaster pool (do you have plaster?). All of your water features also increase pH. I add a gallon/week in the active months. You could work on lowering your T/A but that is a slow process and takes a lot of acid. Maybe do that in the beginning of next season or the end of this season.

 

[YippeeSkippy]

You don't really have to see the exact color, but a *change* in the color. Can you see that?

 

[PoolGate]

pH meters are accurate enough for your needs. They should be calibrated occasionally with a reference solution. You can do that on your own. And T/A as mentioned above you are just looking for that change. From your perspective it will go from darker to lighter. It goes from a pale blue to a fairly bright red.

 

[jesse-99]

I'd like to try and get more input here and bounce back to my original question of, is my pH going up more than normal?

"On early Monday morning, pH was 8.3, and I added about 45 oz. (of 31.45% muriatic acid) based on Pool Math to hit a target of 7.6. Checked it today, it was 8.2. So Pool Math told me to add 60 oz of 31.45% muriatic acid to hit a 7.4 target or so, so I added the 60 oz worth of MA." --- I posted that was yesterday. Today I checked it, even after adding the 60 oz of MA yesterday, my pH still shows 8.2 this morning. I'd have thought it would have gone DOWN? Should I just add another 60 oz worth of MA at this point as Pool Math would tell me to do? I'm just leery about continuing to add the 31.45% MA when pH isn't really dropping?

(Yes my pool is plaster)

EDIT -- I'm wondering if my TA is higher than I think?

 

[PoolGate]

With T/A of 90-120 you'll need about a gallon a week all summer to keep pH down.

 

[mknauss]

New plaster?

Test your TA -- it will be an indicator if your pH testing is incorrect.

 

[CrystalRiver]

Retest the pH 30 minutes after adding acid, pump on. That will tell you if the pH is going down and bouncing back up due to high TA.

 

[jesse-99]

Retest the pH 30 minutes after adding acid, pump on. That will tell you if the pH is going down and bouncing back up due to high TA.

Crystal River --- Thanks. I will try that today by testing it 30 minutes or so after adding the MA. Good idea.

MKnauss --- Pool is about 11 years old roughly. Original plaster (looking at re-doing this in the next year or so). I'm really trying to test TA but it's hard for me. I'm colorblind at the TF-100 test doesn't do much for me. I know everyone hates test strips, but... If i post I picture of a AquaCheck test strip (attached), just to get an "estimate" of my TA, would that help? I think the strip shows that maybe I'm in the 200+ range for TA? My other thought is to take a video of the TA test with TF-100 and make it available online for TFP to watch it, maybe you'll see the colors better than me? (BTW, is wiping the tip clean for the R-0009 absolutely necessary? )

Pool water was filled from a pool water supply company this spring. Not from my well (though maybe 3,000-4,000 gallons of my overall 32,000-34,000 gallons have been filled using my auto-fill). Not sure if TA is due to water or from the plaster, etc. ?

 

[mknauss]

TA is from fill water or if you have added baking soda or soda ash.
Wiping the tip on the R0009 should only be necessary for the first 2 or 3 tests.
The strip is as good as me guessing.
The ph rise is not from your plaster. How often do you run the water features?

 

[jesse-99]

I have 2 waterfalls - both have been turned off for the last 2 weeks. I have a water slide, I run that a couple hours a day usually, to help keep water moving and not too stagnant (plus it pulls water out of my disappearing edge-pit as is then sent up to feed the top of the slide). I also have 2 beach jets that I run for anywhere from 0-4 hours a day as well. I run my filter pump from 7am to 9pm every day (3 skimmers).

 

[PoolGate]

I have 2 waterfalls - both have been turned off for the last 2 weeks. I have a water slide, I run that a couple hours a day usually, to help keep water moving and not too stagnant (plus it pulls water out of my disappearing edge-pit as is then sent up to feed the top of the slide). I also have 2 beach jets that I run for anywhere from 0-4 hours a day as well. I run my filter pump from 7am to 9pm every day (3 skimmers).

How often does the spillover for the disappearing edge run? Do you have pics of that? Sounds like a sweet pool.

 

[cptkirk]

With a SWG and all those water features, you should expect pH to rise, particularly if your TA is also high.

 

[jesse-99]

How often does the spillover for the disappearing edge run? Do you have pics of that? Sounds like a sweet pool.

Poolgate -- Couple hours a day at most ...

CptKirk -- I don't run the water features all the time (see 3 posts up). pH seems to be stabilized around 8.2 or 8.3 and doesn't seem to go up higher than that (so far). I'm hoping that's "okay".... adding Muriatic Acid might bring it down temporarily (I'm checking that today), but a day after adding 60 oz of MA to try and bring it down to 7.6, it's back up to the 8.2 level it previously was 24 hours ago.

I guess I'm wondering if I'm at risk for pH shooting up higher than 8.2 or 8.3 ? It doesn't seem to go much higher on it's own accord that I can tell, so far.

Going to drop another 60 oz MA in to bring pH down, then check pH again after 30-60 minutes to see if it actually came down. If it does come down, and then goes back UP by tomorrow, then is it safe to safe that my TA is bringing it back up?

 

[cptkirk]

Going to drop another 60 oz MA in to bring pH down, then check pH again after 30-60 minutes to see if it actually came down. If it does come down, and then goes back UP by tomorrow, then is it safe to safe that my TA is bringing it back up?

Your water features, SWG, and TA (if it is high) would all contribute to your pH rise. There are folks here who understand water chemistry way better than I do, but my understanding is that there is some value of pH at which your pool will settle for a given set of operating conditions. So it sounds like yours is around 8.2 to 8.3. You don't specify all your test results, but if your TA is high then if you don't knock the pH down with MA regularly you are probably in danger of scaling.

The pH of my pool also drifts up above 8 fairly quickly when left to its own devices, although not as aggressively as yours. I was typically adding a quart of MA every 3 to 4 days. I finally got tired of that and decided to install a CO2 injection system, which has worked well for me so far.

 

[PoolGate]

Your water features, SWG, and TA (if it is high) would all contribute to your pH rise. There are folks here who understand water chemistry way better than I do, but my understanding is that there is some value of pH at which your pool will settle for a given set of operating conditions. So it sounds like yours is around 8.2 to 8.3. You don't specify all your test results, but if your TA is high then if you don't knock the pH down with MA regularly you are probably in danger of scaling.

The pH of my pool also drifts up above 8 fairly quickly when left to its own devices, although not as aggressively as yours. I was typically adding a quart of MA every 3 to 4 days. I finally got tired of that and decided to install a CO2 injection system, which has worked well for me so far.

Poolgate -- Couple hours a day at most ...

CptKirk -- I don't run the water features all the time (see 3 posts up). pH seems to be stabilized around 8.2 or 8.3 and doesn't seem to go up higher than that (so far). I'm hoping that's "okay".... adding Muriatic Acid might bring it down temporarily (I'm checking that today), but a day after adding 60 oz of MA to try and bring it down to 7.6, it's back up to the 8.2 level it previously was 24 hours ago.

I guess I'm wondering if I'm at risk for pH shooting up higher than 8.2 or 8.3 ? It doesn't seem to go much higher on it's own accord that I can tell, so far.

Going to drop another 60 oz MA in to bring pH down, then check pH again after 30-60 minutes to see if it actually came down. If it does come down, and then goes back UP by tomorrow, then is it safe to safe that my TA is bringing it back up?

The important number is the CSI. Can you share your pool test results here using PoolMath? It is an app for your phone. If you click on my name you'll see a link to my poolmath logs.

 

[jesse-99]

Alright so... I went from 8.2 to 7.8 , just 30 minutes or so after adding in 60 oz (6 cups) of MA to the pool. I suspect that come tomorrow morning, pH might jump back to up 8.2 or so. I'm really suspecting my TA is around 200 based on the math involved with the Pool Math app.

So I think I need to lower my TA. 31.45% MA is also supposed to lower TA from what I read (as well as pH) --- correct? FWIW, I've got someone coming over tomorrow that isn't color blind to help me verify my TA, but I'm pretty positive it's around 200 from the math.

(thanks for all the input... I'm learning, slowly).

 

[cptkirk]

Yes, MA will lower the TA as well as lowering the pH. It would be helpful to post a complete set of numbers tomorrow when you get some help with the tests.

 

[jesse-99]

Can do! Thanks all.....

 

[CrystalRiver]

The process for lowering TA is to use acid to lower pH to 7.0 or 7.2, then aerate to let pH rise to 7.8 or 8.0, rinse and repeat. Each time you add acid, that lowers both pH and TA. Aerating raises pH and does nothing to TA. Over time, repeating the process brings the TA down while keeping pH in an acceptable range.