TA and pH yo-yo - Recommended way to handle

[ASteiny]

I apologize, as I'm sure this has been brought up but I have yet to find a good answer. My pool chemistry strategy has been as follows:

• Maintain free chlorine with 10% Sodium Hypochlorite, checking every few days.
• As Sodium Hypochlorite is basic, it will cause my pool's pH to drift upwards. I will check and add concentrated muriatic acid (diluted in 5 gal pail and broadcast over pool) to maintain between 7.4-8.0. I guesstimate that I use 1 gal of muriatic / 2.5 gal of chlorine.
• Periodically check Calcium and CYA, adjusting as needed, especially during changes of season. I adjust Calcium to maintain a good CSI, and adjust CYA to be at least 30 in the winter and 50-60 in the summer.
• Completely ignore TA

I have felt the yo-yo effect of raising TA with baking soda, and then lowering it with acid and have seen no reason to worry about TA, as my pH doesnt drift too fast to handle. However, this seems to be changing, and so I tested TA and got ~30-ppm, which is predictably low. I plan to add baking soda, to get the TA up to ~90, and then use muriatic to get the pH back down, but i predict this will then bring the TA back down? I assume baking soda raises TA more than pH (increases carbonates in pool more than free hydroxide ions). Is there a better way to manage my water chemistry than this? Is there any concern that I could scale out Calcium Carbonate if I add the baking soda too quickly? What pH is ideal to start at before adding baking soda?

 

[Texas Splash]

A TA of 30 is indeed too low, but you don't have to increase it all the way to 90 either. Shoot for a TA of 60 for now and see how that works for your pH. Remember that even though chlorine can appear to influence pH in high FC doses, it's temporary and the pH returns to its previous state once the FC falls back down. This is usually an issue when the FC is raised to 10 ppm or more.

 

[ASteiny]

I apologize, as I'm sure this has been brought up but I have yet to find a good answer. My pool chemistry strategy has been as follows:

• Maintain free chlorine with 10% Sodium Hypochlorite, checking every few days.
• As Sodium Hypochlorite is basic, it will cause my pool's pH to drift upwards. I will check and add concentrated muriatic acid (diluted in 5 gal pail and broadcast over pool) to maintain between 7.4-8.0. I guesstimate that I use 1 gal of muriatic / 2.5 gal of chlorine.
• Periodically check Calcium and CYA, adjusting as needed, especially during changes of season. I adjust Calcium to maintain a good CSI, and adjust CYA to be at least 30 in the winter and 50-60 in the summer.
• Completely ignore TA

I have felt the yo-yo effect of raising TA with baking soda, and then lowering it with acid and have seen no reason to worry about TA, as my pH doesnt drift too fast to handle. However, this seems to be changing, and so I tested TA and got ~30-ppm, which is predictably low. I plan to add baking soda, to get the TA up to ~90, and then use muriatic to get the pH back down, but i predict this will then bring the TA back down? I assume baking soda raises TA more than pH (increases carbonates in pool more than free hydroxide ions). Is there a better way to manage my water chemistry than this? Is there any concern that I could scale out Calcium Carbonate if I add the baking soda too quickly? What pH is ideal to start at before adding baking soda?

Also current readings:
CYA: 50-60-ppm
TA: 30-ppm
pH: 7.6 using a calibrated probe
FC: 3-ppm
CC: 0
Calcium: 325-350-ppm (starts to turn blue at 325, and goes fully blue at 350)

 

[ASteiny]

A TA of 30 is indeed too low, but you don't have to increase it all the way to 90 either. Shoot for a TA of 60 for now and see how that works for your pH. Remember that even though chlorine can appear to influence pH in high FC doses, it's temporary and the pH returns to its previous state once the FC falls back down. This is usually an issue when the FC is raised to 10 ppm or more.

Ok thank you. For the 3 years owning the pool, my pH has steadily drifted upwards and never drifted down. I assumed this was primarly caused by cholrine, but perhaps it is actually dominated by aeration..

 

[Texas Splash]

For the 3 years owning the pool, my pH has steadily drifted upwards and never drifted down. I assumed this was primarly caused by cholrine, but perhaps it is actually dominated by aeration..

Exactly. Aeration certainly will, and sometimes local water top-offs will influence the pH (and TA). I usually have to add about a cup or so of acid every week. Once in a while, if my TA starts to fall to the 40 range, I'll give it a tiny bump back to 60 and I ride along fine for a while.

 

[DMS2014]

Fellow Houstonian, I join you in your TA/pH issues.....

 

[mknauss]

but perhaps it is actually dominated by aeration..

And the TA level of your fill water. When you add fill water, the TA rises, which pushes pH higher.

 

[pjt]

(diluted in 5 gal pail and broadcast over pool)

Don't premix acid in a pail. You want to minimize handling/transferring MA. The more you handle it, you increase the risk of a spill/splashout etc.. In front of a return with the pump running, just hold the bottle right above the water and slowly pour the MA (pencil stream) directly from the bottle into your pool. I let the bottle rest on the surface of the water and position the bottle opening about an inch or two above the water. The MA mixes quickly with the water. After adding MA, you can brush the area if desired to spread the MA around.

I tested TA and got ~30-ppm

How are you testing?

Completely ignore TA

Maintain awareness of TA, but don't chase it. I wouldn't let TA get below 50. As much as I try, I can't get my TA below 70. I wish I could get it down to 50. What's the pH, TA, and CH of your fill water?

 

[tim5055]

I will check and add concentrated muriatic acid (diluted in 5 gal pail and broadcast over pool)

No need to dilute in a bucket first. This just adds a step to spill it.

Here is my acid methodology -


Safety first.

Wear old clothes and eye protection.

I like to get in front of a return on my hands & knees and splash a little pool water on the pool deck.

Then open the acid bottle and partially submerge it in the water.

Tilt the bottle to pour the acid in at close to water level, but don't let the bottle get submerged. I don't measure because it's an additional step for me to spill the stuff.

Remove the bottle from the water and set it down in the puddle on the pool deck while you replace the cap. Try not to breathe the fumes.. Guess a little low on amount you need, then test again after it circulates well. You can always add more.

 

[Mikey0214]

No need to dilute in a bucket first. This just adds a step to spill it.

Here is my acid methodology -


Safety first.

Wear old clothes and eye protection.

I like to get in front of a return on my hands & knees and splash a little pool water on the pool deck.

Then open the acid bottle and partially submerge it in the water.

Tilt the bottle to pour the acid in at close to water level, but don't let the bottle get submerged. I don't measure because it's an additional step for me to spill the stuff.

Remove the bottle from the water and set it down in the puddle on the pool deck while you replace the cap. Try not to breathe the fumes.. Guess a little low on amount you need, then test again after it circulates well. You can always add more.

I’m new at this too. Serious question, how are you suppose to know what 3.5 pints is when you are pouring it out of a gallon jug slowing into the pool in the size of a pencil stream ? I feel like I would have to measure in order not to totally mess it up.

We filled our plaster pool on Saturday and the pool company added acid on Tuesday. My ph is right around 7.4 and I am anticipating adding some soon.

Thanks again!

 

[tim5055]

I’m new at this too. Serious question, how are you suppose to know what 3.5 pints is when you are pouring it out of a gallon jug slowing into the pool in the size of a pencil stream ? I feel like I would have to measure in order not to totally mess it up.

We filled our plaster pool on Saturday and the pool company added acid on Tuesday. My ph is right around 7.4 and I am anticipating adding some soon.

Thanks again!

I admit, it's a guess. Play in the kitchen pouring water out of measuring cups. Before I found (I admit, I stole this advice) this method I ruined multiple shirts and short from a small splash of acid.

Pool ownership is a learning experience. None of us got it right at first or maybe even ever. The nice thing is that the difference between 7.6 and 7.2 is not going ot destroy your pool. None of our numbers are cast in stone. It's all a range. A little off today can be fixed tomorrow. Real damage only comes from ignoring it for weeks/months.......

 

[reggiehammond]

I’m new at this too. Serious question, how are you suppose to know what 3.5 pints is when you are pouring it out of a gallon jug slowing into the pool in the size of a pencil stream ? I feel like I would have to measure in order not to totally mess it up.

We filled our plaster pool on Saturday and the pool company added acid on Tuesday. My ph is right around 7.4 and I am anticipating adding some soon.

Thanks again!

You don’t need to be precise; so eyeball it and call it good. It’ll average out over time. pH in the 7’s is all you’re trying to do.

 

[ghall6292]

I used to obsess about getting the exact amount in as well. Always carefully measured. Then, one big whiff of the acid was enough for me to abandon that practice! Several on here gave me the same advice you're getting. When dealing with chemicals, safety trumps everything else.

With time and practice, (and firing the pool boy and forgetting how to get to the pool store!) everything eventually becomes less stressful, and trends become more of an issue than specks, millimeters, decimal points, etc. Seems somewhat sacrilegious, but that's how it's working for me, now in my third year of my TFP transformation. If something seems too mysterious, there's always 310,457 members who may have a little experience to help me out!

 

[SoDel]

I’d say the bottom line when working with strong acids is be careful. Use whatever method you are comfortable with (and good at). Yes, measuring and diluting acid does increase risk of an errant splash. Work in a manner that avoids this.

Holding a bottle of undiluted acid over or in the water risks it slipping in your hand and getting water in it (which can cause it to boil and depending on how full the bottle is, shoot violently out of the bottle and possibly at or on you).

Whatever method used, be aware of the risks and manage them appropriately (don’t be careless, wear appropriate PPE, and everything will be fine).