Lowering TA with Dry Acid Or Muriatic Acid

[CelticDaddio]

My TA is currently 230. It was recommended on another forum that I lower it according to the "HOWTO: Step-by-Step Guide to lowering your alkalinity" sticky. I read in my copy of "The Ultimate Guide to Pool Maintenance" by Terry Tamminen that you can lower TA by adding Muriatic Acid, or Dry Acid. Anyone try that?

Ed

[JohnT]

Sure adding acid lowers your TA. It also lowers your pH. When the pH goes back up, the TA goes with it, but when you aerate while the pH is low, the TA stays down.

[CarlD]

Tamminen gives the typical garbage the pool industry gives you. They love the "slug of Muriatic Acid" approach and give you a MacBeth Witches' explanation for why it works. If it does, it's incidental.

There's really only one way, short of dilution with low T/A water to lower T/A and that's what's here. It's not always clear so here's how you do it:

1) Lower pH to 7.0-7.2. (Muriatic or dry acid are both fine) This lowers T/A somewhat.

2) Aerate your water. This raises pH WITHOUT raising T/A--and it's the ONLY WAY TO DO IT!

3) Lower your pH again to 7.0-7.2, bringing T/A down some more.

4) Aerate to raise pH again without raising T/A.

5) Repeat until T/A is in the desired range.

You "ratchet" your T/A down. T/A and pH are linked. pH goes up, T/A goes up. pH goes down, T/A goes down. ONLY BY AERATION can you break that cycle and do the raising of the pH without raising T/A, allowing you to lower it more the next cycle.

The "standard" method only works if you have inadvertent aeration to raise pH that makes it look like it worked.

Worse, the "Slug" of Muriatic Acid can do major, even catastrophic damage to your pool. If that "slug" comes to rest on a vinyl liner, with its 30% concentration of HydroChloric Acid, it can dissolve your liner or weaken it enough to fail.

[CelticDaddio]

How do I aerate the pool?

Ed


Tamminen gives the typical garbage the pool industry gives you. They love the "slug of Muriatic Acid" approach and give you a MacBeth Witches' explanation for why it works. If it does, it's incidental.

There's really only one way, short of dilution with low T/A water to lower T/A and that's what's here. It's not always clear so here's how you do it:

1) Lower pH to 7.0-7.2. (Muriatic or dry acid are both fine) This lowers T/A somewhat.

2) Aerate your water. This raises pH WITHOUT raising T/A--and it's the ONLY WAY TO DO IT!

3) Lower your pH again to 7.0-7.2, bringing T/A down some more.

4) Aerate to raise pH again without raising T/A.

5) Repeat until T/A is in the desired range.

You "ratchet" your T/A down. T/A and pH are linked. pH goes up, T/A goes up. pH goes down, T/A goes down. ONLY BY AERATION can you break that cycle and do the raising of the pH without raising T/A, allowing you to lower it more the next cycle.

The "standard" method only works if you have inadvertent aeration to raise pH that makes it look like it worked.

Worse, the "Slug" of Muriatic Acid can do major, even catastrophic damage to your pool. If that "slug" comes to rest on a vinyl liner, with its 30% concentration of HydroChloric Acid, it can dissolve your liner or weaken it enough to fail.

[JohnT]

How do I aerate the pool?

Ed

A fountain, point the returns at the surface, or get a bunch of kids in there to splash around.

[CelticDaddio]

You mean just a plain ol' fountain like this:

http://images.intheswim.com/images/cat_image/A5500.jpg

And point the skimmer returns up to the surface?

Ed


A fountain, point the returns at the surface, or get a bunch of kids in there to splash around.

[CarlD]

That's all you need!

[CelticDaddio]

So my procedure to lower my TA is

1) Lower pH to 7.0-7.2. (Muriatic or dry acid are both fine) This lowers T/A somewhat.
2) Turn on the fountain
3) Lower pH again to 7.0-7.2, bringing T/A down some more.
4) Turn on the fountain again
5) Repeat 1-4 until T/A is in the desired range.

Is there a formula for how much Muriatic acid, or dry acid to add to reduce the ph? I.e. 1/4 cups of muriatic reduces pH by 0.5, or is it not that simple?


That's all you need!

[CarlD]

So my procedure to lower my TA is

1) Lower pH to 7.0-7.2. (Muriatic or dry acid are both fine) This lowers T/A somewhat.
2) Turn on the fountain
3) Lower pH again to 7.0-7.2, bringing T/A down some more.
4) Turn on the fountain again
5) Repeat 1-4 until T/A is in the desired range.

Yup that's it.

[Watermom]

In a 33,000 gallon pool, it is going to take about 26 oz. of muriatic acid to lower the ph by approximately 0.2. Don't try and get to your target in one dose. Small doses (maybe a pint at a time) added in front of a return jet slowly. Be careful not to splash any on you or on your liner. Also, don't breathe the fumes. Wait several hours to let it circulate, then retest and redose as needed.

[CelticDaddio]

Until my wife decides on a purty fountain, will this do the job? :D

http://celticblues.com/images/fnt3.jpg

Seriously, though, does this serve the purpose? Should I put more holes in the end cap... i.e. add more streams?

Ed


Yup that's it.

[Longgrove]

It's been awhile since I visited the forum. I have had great success following the recommendations here. Glad to see it's alive and well.

18,000 FG IG

My TDS got too high (could that be from using bleach (93% salt) all these years?) so had to drain a little more than half and truck in 10,000 gallons of water this morning.

My TA is high (210) on my first test. PH is 7.2. Should I wait for everything to settle down before adjusting. Or should I start lowering PH and begin aerating now? How do you calculate the amount of muriatic acid to lower .2?

Can you shock while adjusting PH (adding acid)?

[NWMNMom]

I might be over paranoid, but why would you want to lower your PH much more than where it is? Get too much more acidic and maybe risk some damage...I would just aerate to get the TA down.

[Watermom]

Aeration doesn't lower TA. Aeration raises ph.

Check out this link.

http://www.poolforum.com/pf2/showthread.php?t=6746

[aylad]

For CelticDaddio yes, what you have pictured there will help...anything that gets the water moving at or above the surface will work.

For longgrove, glad to see you back. Just FYI, you'll probably get more useful responses to your question if you'll start your own thread instead of adding to another one. In answer to your questions, you can go ahead and lower your pH and begin aeration, just make sure you don't drop it too low. I would not shock the pool while in the TA lowering process--the higher chlorine levels tend to skew the pH readings, making them falsely high. You don't want to take that chance when you're dealing with pH at the bottom of the acceptable range to begin with.

Janet

[CelticDaddio]

I am confused. In this thread http://www.poolforum.com/pf2/showthread.php?t=7546 you told me my TA was too high and to read the
"HOWTO: Step-by-Step Guide to lowering your alkalinity" sticky. Having read that I thought that aeration did lower the TA, but now re-reading I have a different understanding (or mis-understanding).

Is it the acid you add that lowers the pH that also lowers the TA? Do we then aerate to raise the pH without raising the TA as well? Is it the combination of these two things (aeration and acid) which effectively lowers the TA but keeps the pH at the right level?

Ed


Aeration doesn't lower TA. Aeration raises ph.

Check out this link.

http://www.poolforum.com/pf2/showthread.php?t=6746

[CarlD]

Ed,
The original sticky Ben put up is confusing and leads you to think the aeration lowers T/A. It does NOT.

T/A is connected to pH, and when you lower pH it pulls down T/A. When you raise pH, it bounces back up again.


BUT, when you aerate, you gas off carbonic acid as CO2 (like making soda flat) and that allows pH to rise WITHOUT T/A going up with it. Waterbear has a great explanation of the chemistry in The China Shop.

BTW, Ed, that's got to be the absolute A-Number One UGGGLIEEST home-made fountain I've ever seen!:eek: Congratulations, guy!:D (though I think the monstrosity Robert DeNiro gives Billy Crystal in "Analyze This" has it beat hands down!)

But it's clever and practical and should work GREAT to gas off the carbonic acid and raise your pH--and that's really all that's important.

Carl

[CelticDaddio]

Thanks, I'll take clever over pretty any day. And it cost me no additional $... Already had everything from when I moved my filter/pump/etc last fall (That was a pain!)

Ed


Ed,
The original sticky Ben put up is confusing and leads you to think the aeration lowers T/A. It does NOT.

T/A is connected to pH, and when you lower pH it pulls down T/A. When you raise pH, it bounces back up again.


BUT, when you aerate, you gas off carbonic acid as CO2 (like making soda flat) and that allows pH to rise WITHOUT T/A going up with it. Waterbear has a great explanation of the chemistry in The China Shop.

BTW, Ed, that's got to be the absolute A-Number One UGGGLIEEST home-made fountain I've ever seen!:eek: Congratulations, guy!:D (though I think the monstrosity Robert DeNiro gives Billy Crystal in "Analyze This" has it beat hands down!)

But it's clever and practical and should work GREAT to gas off the carbonic acid and raise your pH--and that's really all that's important.

Carl

[Watermom]

Ed,
Just to keep the threads from getting really long, it is best not to always include the whole previous post quoted in your replies. Of course, there are times when you need to quote a part of one and that is fine.

Thanks and enjoy your pool!

[NWMNMom]

Ok, good - so this clarifies the situation for our pool, which is just the opposite - I do NOT want to aerate my pool as it will make my PH rise, its too high already, I want my TA and PH to both go down so acid is the answer for me. It was just explained to me but a bit different route in another thread on TFP and this seals it. Good to know. (BTW, it likely got that high due to 10" plus of rain in the last 2 wks, the salt and the bleach - TA started out on the high end)

[CarlD]

Thanks, I'll take clever over pretty any day. And it cost me no additional $... Already had everything from when I moved my filter/pump/etc last fall (That was a pain!)

Ed

And it is very clever!;)

[Longgrove]

Update: I added 1/8 gallon of muriatic acid last night... pointed 3 returns upward and increased water flow to the hot tub waterfall (into the pool) to help aerate. Readings were TA 180/PH 7.4 this at 9 AM.
So added another 1/8... in addition to the waterfall and returns adjusted upward, I turned on the blower in the hot tub, and turned on Polaris cleaner pump (without cleaner attached)... lots of water movement. Readings at 2:30 are TA 140/PH 7.4.
Is this to good to be true? Seems to be happening fairly quickly and with far less than the three gallons the pool store told me I'd need. Should I expect a rebound? What do the experts think? What should I do next?

BK

[CarlD]

BK,

It sounds like everything is working EXACTLY the way it should. You are almost done!

Pool stores tell you to put in LOTS of chemicals--they SELL them to you. You put them in, overshoot by a mile your target, they sell you something else, continuing the cycle.

When I got my first pool I bought the book they sell "Taming The Pool Monster". It was useless and worthless. I don't even know where it is.

I test and check my water all the time, and stay ahead of problems--and I do NOT take pool store clerks' advice.

[aquarium]

I made this one:

http://i18.photobucket.com/albums/b113/tomwood2/pools/fountainpipe.jpg

http://i18.photobucket.com/albums/b113/tomwood2/pools/fountainwater.jpg

The valve isn't even necessary so it could be simpler. Works very fast if you stay on top of the pH with the acid.

[TheG$]

So what effect would an in line "ozonotar" have on the aeration process? (In other words assume I need to Lower TA a lot but need to keep pH where she is now basically).

My assumption is, it is already performing that aeration to a large degree. But not knowing how the introduction of O3 may effect the offgas of Co2, I am not sure. Thoughts?

[chem geek]

The ozone will get converted to oxygen gas rather quickly and will essentially outgas oxygen from the pool (and such oxygen bubbles will pull carbon dioxide from the pool) since it is already saturated in oxygen (from being in equilibrium with oxygen in the air). I do not know the rate of ozone generation in a typical ozonator so can't comment on how good it is at aeration compared to an SWG. You could certainly try the TA lowering process with the ozonator off and on at different times and compare the rate of TA lowering. It's clearly going to be better with it on than off -- I just don't know by how much.

Richard

[waterbear]

Tamminen gives the typical garbage the pool industry gives you. They love the "slug of Muriatic Acid" approach and give you a MacBeth Witches' explanation for why it works. If it does, it's incidental.


Tamminen doesn't actually advocate the 'slug method' in his book. He just gives some treatment tables that show how much muriactic acid or dry acid is needed to lower a certain amount of TA in a given volume of water and doesn't really say much more on the subject. All references he makes about adding acid always say to add it in small amounts so as not to make too great a pH change at once and to 'walk' the acid around the pool or pour it slowly into the return stream with the pump running so it gets diluted quickly and to never pour it near drains, skimmers,and other suction inlets. Basically the same advice that has been given on this board time and again. His advice might not be complete (his whole chapter on water chemistrt is VERY basic) but it is generally sound.

[peggles0224]

:confused: I have borderline Alk reading of 70 and 7.9 PH... How much baking soda do I had to raise Alk and how much Muriatic acid do I had to lower PH

[CarlD]

:confused: I have borderline Alk reading of 70 and 7.9 PH... How much baking soda do I had to raise Alk and how much Muriatic acid do I had to lower PH

Say you have a 15,000 gallon pool. Start with 1 lb of baking soda and 1 cup of muriatic acid. I'd add them at least an hour apart (acid first), then wait a few hours (say 6?) and measure pH and T/A again. Go slow, use a little bit at a time so you don't overshoot targets. If you lower pH from 7.9 to 7.3, T/A should come down still further.

[sam98177]

I'm having problems with the pH being at the higher limit and the TA being too high:

Here's my test results from this morning:

FC = 6
CC = .2
pH = 7.8
TA = 200
CH = 300
CYA = 35

I posted earlier results in another thread, but I think I should have posted them here. I seem to can't lower the pH and TA much. I haven't tried the acid stuff yet.

Yesterday morning, my FC = .4 and the CC = .2 My floatie was almost empty and I added the pucks.

I'm using 4 3" Pace Pucks in a floatie, and I shocked the pool yesterday afternoon, with a 1.75 gallon of Clorox.

Anyways, I'm trying to get the TA and pH down to a better reading. I've seen the posts on how to do such.

My questions are: How much acid do I use at a time to decrease the pH and TA.

Where is the best place to get the dry acid. I know where to get the liquid acid, but I think I need the dry acid because I have a fiberglass pool, or is does it really matter?

I have DE filter, which was completely washed and filled with new back in May or early June.

After I can realize my pH and TA at a lower reading, I'm going to do the aeration thing. I like the valve jig that Aquarium made. I'll do something similar too. My return lines dont have threads, so I'll figure something out.

Thanks,

Sam

[waterbear]

I'm having problems with the pH being at the higher limit and the TA being too high:

Here's my test results from this morning:

FC = 6
CC = .2
pH = 7.8
TA = 200
CH = 300
CYA = 35

I posted earlier results in another thread, but I think I should have posted them here. I seem to can't lower the pH and TA much. I haven't tried the acid stuff yet.
Adding acid is the ONLY way to lower pH and TA.
Yesterday morning, my FC = .4 and the CC = .2 My floatie was almost empty and I added the pucks.

I'm using 4 3" Pace Pucks in a floatie, and I shocked the pool yesterday afternoon, with a 1.75 gallon of Clorox.
Be ware of the pace tabs. They contain copper!
Anyways, I'm trying to get the TA and pH down to a better reading. I've seen the posts on how to do such.

My questions are: How much acid do I use at a time to decrease the pH and TA.
How big is your pool? A good rule of thumb is to add a pint for each 10000 gallons of water (with pump running), wait about 30 minutes and test the pH. Repeat until pH is where you want it.
Where is the best place to get the dry acid. I know where to get the liquid acid, but I think I need the dry acid because I have a fiberglass pool, or is does it really matter?
You can use muriatic acid in a fiberglass (or any type) of pool and it is actually preferable to dry acid (sodium bisulfate, pH down, pH minus, etc.) since it will not add any sulfates to the water. You can get dry acid at any pool store or in the pool dept of such places as Walmart, Home Depot, Ace Hardware, Lowes, etc.

Dry acid is 'nicer' to use (no fumes) but it is much more expensive and not as effective (you need a LOT more of it). It really is just as dangerous as the muriatic acid, it just doesn't fume.
I have DE filter, which was completely washed and filled with new back in May or early June.

After I can realize my pH and TA at a lower reading, I'm going to do the aeration thing. I like the valve jig that Aquarium made. I'll do something similar too. My return lines dont have threads, so I'll figure something out.
If you want to lower TA then drop your pH to 7.0, test your TA and start aerating. Monitor the pH and when it starts to rise drop it back down to 7.0 and test the TA. Keep this up until the TA is where you want it when you test and then stop adding any more acid and just aerate until the pH climbs back up to 7.6.
Thanks,

Sam
Hope this helps.