pH test help

[Mattikuss]

Hi friends,

I’ve got my trusty TF-Pro test kit, ever since, my chlorine and CYA levels have been perfect. Tested my total alkalinity tonight and it came back at 240… whoa. So, I tested my pH to verify but realized it’s not a very accurate test and is subject to interpretation. It also maxes out at 8.2. Two questions:

1) within this test kit is there a more accurate test for pH?
2) what on earth do I do about a TA at 240?

 

[kul]

Are you sure the TA is that high? If you have a new kit be sure to wipe the bottle when adding drop by drop to measure TA. Not doing so can cause elevated TA reading.

The ph looks like 8.2 to me. Could be higher but I recommend dosing with MA to get into the 7 range. Then test again.

 

[Mattikuss]

Oh, and I should include my pool math screenshot

 

[Mattikuss]

Are you sure the TA is that high? If you have a new kit be sure to wipe the bottle when adding drop by drop to measure TA. Not doing so can cause elevated TA reading.

okay, I’m glad you mentioned the bottle thing. Why? I don’t understand how not wiping the bottle causes an issue.

 

[kul]

I believe it has something to do with initial static. After a few tests you don’t have to do the wiping thing anymore.

 

[Mattikuss]

I believe it has something to do with initial static. After a few tests you don’t have to do the wiping thing anymore.

Okay, I’ll try again, be back in 4 minutes.

 

[Mattikuss]

Okay, I’ll try again, be back in 4 minutes.

Yes, 22 drops of R-0009 and I got this:

 

[kul]

The color should be Barbie hot pink when the test is complete. If your TA is still high the way to lower it is to lower your ph with MA. This will also lower your TA to some extent (poolmath does this calculation for you). You then need to aerate to increase your ph again and use MA to get it back in range. Repeat as needed until you have the TA you’re aiming for. Does that make sense?

What’s your CSI? The TA mostly matters as it relates to your CSI. If the CSI is fine I wouldn’t mess too much with ideal numbers for TA.

 

[kul]

Have you ever tested your fill water to see how much TA it has? Sometimes it helps to know what is in the water you add for top offs.

 

[Mattikuss]

The color should be Barbie hot pink when the test is complete. If your TA is still high the way to lower it is to lower your ph with MA. This will also lower your TA to some extent (poolmath does this calculation for you). You then need to aerate to increase your ph again and use MA to get it back in range. Repeat as needed until you have the TA you’re aiming for. Does that make sense?

What’s your CSI? The TA mostly matters as it relates to your CSI. If the CSI is fine I wouldn’t mess too much with ideal numbers for TA.

Okay, so by lowering pH with MA (according to pool math I need 51 oz at 29%) I am simultaneously lowering TA. Got it. What l don’t get is why I can’t just add a specific amount of MA to properly balance the pH and TA. It sounds like they are both reduced by MA

Also, what is aerating? I poke holes in the water? lol, kidding.

 

[Mattikuss]

Have you ever tested your fill water to see how much TA it has? Sometimes it helps to know what is in the water you add for top offs.

No, I have not, we have used the pool 8 of the last 9 days and I haven’t added any water. I’m guessing that it won’t have a massive impact based on volumes but I could be wrong. We use city water.

 

[kul]

You can’t go wild with MA because you don’t want to have your ph plummet below 7 range. It can make your water corrosive. You have to go slow.

To aerate point all return jets up to make bubbles come up to the surface. If you have a spill over or any fountains you want those on too. This agitation will aerate the water thus causing your ph to increase. Once it increases to 8.2 again start over with MA with enough dosage to drop it to 7.2 then repeat as needed until your TA reading is where you need it to be.

 

[mknauss]

PH TA Relationship - Further Reading

www.troublefreepool.com

 

[Mattikuss]

You can’t go wild with MA because you don’t want to have your ph to plummet below 7 range. It can make your water corrosive. You have to go slow.

To aerate point all rerun jets up to make bubble come up to the surface. If you have a spill over or any fountains you want those on to. This agitation will aerate the water thus causing you ph to increase. Once it increases to 8.2 again start over with MA with enough dosage to drop it to 7.2 then repeat as needed until your TA reading is where you need it to be.

Wow, this is fantastic. So aerating essentially adds O2 to the -OH molecules thereby neutralizing the acidity and raising pH. Makes perfect sense to me now. This was educational and I appreciate your help. Last question: if I’m using pool math app to determine amount of MA to add, should I trust that number or err on the side of caution and go slightly less so as not to acidify my water.

 

[Mattikuss]

Wow, this is fantastic. So aerating essentially adds O2 to the -OH molecules thereby neutralizing the acidity and raising pH. Makes perfect sense to me now. This was educational and I appreciate your help. Last question: if I’m using pool math app to determine amount of MA to add, should I trust that number or err on the side of caution and go slightly less so as not to acidify my water.

***H+ not -OH

 

[kul]

if I’m using pool math app to determine amount of MA to add, should I trust that number or err on the side of caution and go slightly less so as not to acidify my water.

You can trust the pool math app for acid dosing recommendations as long as you have it set up with the correct number of gallons for your pool.

Also read the article posted above because it will help.

 

[sande005]

Definitely test your tap water. I remember Rochester having water back in the day (long time ago) that needed a LOT of treatment. So it may be naturally added to the pool. If the test comes back with low or very low TA, at least you can eliminate that as one source of the problem.

 

[sande005]

***H+ not -OH

I think it has more to do with the removal of CO2 (ie Carbonic Acid), which thereby increases pH, rather than messing with the water molecules...
There are some old posts by a member known as Chem Geek that go really deep into the chemistry. Pools tend to be a bit carbonated, so any aeration increases surface area and allows the CO2 to more quickly get into equilibrium with the atmosphere.

 

[Mattikuss]

I think it has more to do with the removal of CO2 (ie Carbonic Acid), which thereby increases pH, rather than messing with the water molecules...
There are some old posts by a member known as Chem Geek that go really deep into the chemistry. Pools tend to be a bit carbonated, so any aeration increases surface area and allows the CO2 to more quickly get into equilibrium with the atmosphere.

Awesome! I’ll try to dig it up. I love this community. So helpful.

 

[Bperry]

Awesome! I’ll try to dig it up. I love this community. So helpful.

I might suggest doing the TA test with the 10ml sample and adjusted drop counts. Or at least double check you aren’t using the 25ml size with the 10ml drop counts.