How much and how often can muriatic acid be added?

[kma_97]

Hi all,

(tested at Leslie’s)

pH: 8.1
TA: 350
Pool: 34,000 gal
SWG: IC-60

Water comes from the well. TA in the well is even higher. Have been trying to lower both for some time by adding 55 fl oz of muriatic with the pump running and then waiting for 4 hrs, retesting and adding as needed.

How much muriatic acid can I add at any time and how often can I add it? Do I need to wait for 4 hrs or can I shrink this to 2 hrs or less? What’s the recommended pump speed?

Thank you!

 

[PoolStored]

WELCOME TO TFP!

Let me start this by saying we don't give chemical adjustment advice (like how much to add of what) without using one of our recommended test kits. You can read about them here to decide which one is best for you (the blue is a link) --> Test Kits Compared

Why? We only give advice based on these kits.
Really? Why? We have found pool store and other test kits do not give accurate and consistent results.
So what? Maybe it will be close enough...Well, maybe, and maybe not. We could actually give you advice, based on inaccurate testing, that will make your situation worse, or tell you to do something you don't actually need to do.

Some good reading to get you started: Pool Care Basics

How much muriatic acid can I add at any time and how often can I add it?

Muriatic lowers TA, yes, however it also lowers pH. We recommend that, until you know your pool, that you limit your muriatic addition to not lower pH more than .4 at one time, and never lower your pH below 7. Below 7 and you can start damaging your pool and equipment.

Do I need to wait for 4 hrs or can I shrink this to 2 hrs or less?

30 minutes is sufficient between additions. However, if you are thinking that simply by adding a whole bunch of Muriatic that you will lower your TA, you will end up reducing your pH to damaging levels before you lower your TA the amount you are expecting. You can read this:

Lower Total Alkalinity

A lower Total Alkalinity level can help a pool owner stabalize their pH increase. We'll explain how to lower TA with a little help from muriatic acid.

www.troublefreepool.com

What’s the recommended pump speed?

It really doesn't matter.

Proof is in the pudding! -->How Clear is TFP Clear?

 

[bertschb]

How much muriatic acid can I add at any time and how often can I add it?

When we bought our house last December our TA was 240. I added acid 2-3 times a week. I would wait for pH to get to around 7.8 then add enough acid to drop it to around 7.4.

Doing this, it took six weeks to get my TA down to 80. I went through several gallons of 31% acid.

 

[kma_97]

Thank you, both!

When we bought our house last December our TA was 240. I added acid 2-3 times a week. I would wait for pH to get to around 7.8 then add enough acid to drop it to around 7.4.

Doing this, it took six weeks to get my TA down to 80. I went through several gallons of 31% acid.

How much were you adding at a time? Based on Pool Math, I should add a total of 167 fl oz of 31.45% Muriatic and based on "... limit your muriatic addition to not lower pH more than .4 at one time" advice above, Pool Math calculates it to be 55 fl oz. I've been adding 55 fl oz of 31.45% twice daily. pH went down from 8.4+ to 8.1 (so far I've added 4 Gal). Alkalinity won't budge... Assuming I monitor pH religiously and do not allow it to fall below 7.0 (maybe lower it to and keep it at 7.2), can I pour 55 fl oz (mixed with a 3/4 of a 5 Gal bucket of water) in front of 3 return jets, circulate 30 min, retest, repeat every 30 min until alkalinity is acceptable or pH hits 7.0-7.2 mark?

 

[Toxophilite]

When you get your test kit, it and Pool Math will tell you how much, as well as you learning your pool's needs and reactions.

With TA that high, you could be at this for weeks to get TA down.

 

[bertschb]

How much were you adding at a time? ...Alkalinity won't budge... Assuming I monitor pH religiously and do not allow it to fall below 7.0....., can I pour 55 fl oz ..., circulate 30 min, retest, repeat every 30 min until alkalinity is acceptable or pH hits 7.0-7.2 mark?

I was adding 30-40oz at a time. You won't be able to keep adding acid every 30 minutes because eventually you'll get pH down to around 7.2 or 7.4 at which point you should stop adding acid. You then need to let pH creep back up to around 7.8. In my pool that took a day or two. You can speed up the pH rise a bit by aerating the water.

Trying to lower TA was one of the first things I came to this forum for help on as a new pool owner. The advice I got at that time was to be patient as it could take several weeks. They were right! You can't really speed the process up because pH would drop too low if you add too much acid too frequently.

I don't like adding acid so I ended up installing an acid pump (Pentair IntelliPH). My acid pump is currently set to add 31oz of acid per week.

 

[kma_97]

When you get your test kit, it and Pool Math will tell you how much, as well as you learning your pool's needs and reactions.

With TA that high, you could be at this for weeks to get TA down.

That's not really answering my question and Pool Math does not tell how much can be added at one time...

1. Assuming I had said test kit and it produced the same results as posted in my original question, I am not asking "should I add all 167 fl oz at one once", but:
   "What is the maximum that can be added at one time (assuming results are produced by the recommended test kit and the target is still 167 fl oz)"?
2. Can I, without damaging the pool or equipment:
   1. Add 55 fl oz (mixed with a 3/4 of a 5 Gal bucket of water) in front of 3 return jets
   2. Run the pump for 30 min
   3. Test
   4. If pH <=7.2 or TA is within the target range, abort until pH is >= 7.5
   5. Repeat steps 1-4 until TA is within the target range

?

 

[kma_97]

I was adding 30-40oz at a time. You won't be able to keep adding acid every 30 minutes because eventually you'll get pH down to around 7.2 or 7.4 at which point you should stop adding acid. You then need to let pH creep back up to around 7.8. In my pool that took a day or two. You can speed up the pH rise a bit by aerating the water.

Trying to lower TA was one of the first things I came to this forum for help on as a new pool owner. The advice I got at that time was to be patient as it could take several weeks. They were right! You can't really speed the process up because pH would drop too low if you add too much acid too frequently.

I don't like adding acid so I ended up installing an acid pump (Pentair IntelliPH). My acid pump is currently set to add 31oz of acid per week.

Thank you!

 

[PoolStored]

Thank you, both!


How much were you adding at a time? Based on Pool Math, I should add a total of 167 fl oz of 31.45% Muriatic and based on "... limit your muriatic addition to not lower pH more than .4 at one time" advice above, Pool Math calculates it to be 55 fl oz. I've been adding 55 fl oz of 31.45% twice daily. pH went down from 8.4+ to 8.1 (so far I've added 4 Gal).

How are you testing to get an 8.4 reading? Pool store? I can't tell you what to add, I would STOP. Do nothing until you get a good test kit. Please, you can be doing more damage to your pool and equipment if you are basing it on pool store testing. Adding that much acid in a short period of time could be significant issue (or it could not, we just don't know). Per pool math, 4 gallons would lower your pH by 3.6. Over what period of time did you add this acid? Four days?

Alkalinity won't budge... Assuming I monitor pH religiously and do not allow it to fall below 7.0 (maybe lower it to and keep it at 7.2), can I pour 55 fl oz (mixed with a 3/4 of a 5 Gal bucket of water) in front of 3 return jets, circulate 30 min, retest, repeat every 30 min until alkalinity is acceptable or pH hits 7.0-7.2 mark?

Yes, you can do this and repeat until it gets to 7.0, then let it rise again. However, I can't say this emphatically enough, please do not add any more muriatic acid to your pool until you get a test kit. I can link to DOZENS of threads here on pool store testing results being inaccurate. Here is just one (see below). pH from pool store was 8, actual was 7.4. You make more muriatic additions with discrepancy like this (if your pool is actually 7.4) you will potentially do damage to your equipment. In this example, pool store TA test was way off also.

Another pool store vs home testing thread

Out of curiosity I took a sample to Leslie's today to compare their "AccuBlue" machine to my own tests using the TF-100 (plus a digital pH meter). Collected a large sample and split it in half, tested half myself, filled a sample bottle with the other half and took it to the Leslie's down the...

www.troublefreepool.com

 

[PoolStored]

That's not really answering my question and Pool Math does not tell how much can be added at one time...

1. Assuming I had said test kit and it produced the same results as posted in my original question, I am not asking "should I add all 167 fl oz at one once", but:
   "What is the maximum that can be added at one time (assuming results are produced by the recommended test kit and the target is still 167 fl oz)"?

We generally recommend only dropping pH no more than .4 in one go. This is to protect new users that may not know their pool size, maybe have a concentration of muriatic that is unknown. You can always add more 30 minutes after your last addition and another test. If you ABSOLUTELY know YOUR pool, it is safe to add enough to reduce your pH to 7.0. However, our test kits are only accurate up to ph 8.0. If you are 8.0 or above, you need to reduce in .4 increments until you are back into the 7s. THEN you can add enough if you know your pool to get to 7.0 If you "guess" that it is 8.4 and it is actually 8 and you add to get to 7, you can get into the 6s.

1. Can I, without damaging the pool or equipment:
   1. Add 55 fl oz (mixed with a 3/4 of a 5 Gal bucket of water) in front of 3 return jets

Depends on your starting point and your pool size. If it will not reduce pH below 7, then yes.

1. 1. Run the pump for 30 min

30 minutes is great.

1. 1. Test

ABSOLUTELY!!!!

1. 1. If pH <=7.2 or TA is within the target range, abort until pH is >= 7.5

Yes, but avoid 6s. WHEN you get your test kit, add in smaller increments until you are accurate with your additions.

1. 1. Repeat steps 1-4 until TA is within the target range

?

Yes, you have the general process correct.

We may come across as rigid with the test kits. We are like doctors here...unwritten motto...DO NO HARM. What you are doing without a test kit has the potential to do harm to your pool/equipment. I can't tell you how many pools that we have helped people recover because of pool stores and pool store testing and recommendation. Over 100,000 with 300,000+ members. Ask me why I am PoolStored. We ACTUALLY care about you and your pool and we NEVER want someone to have damage to their pools based on advice received here.

 

[bertschb]

Can I, without damaging the pool or equipment:

1. Add 55 fl oz (mixed with a 3/4 of a 5 Gal bucket of water) in front of 3 return jets
2. Run the pump for 30 min
3. Test
4. If pH <=7.2 or TA is within the target range, abort until pH is >= 7.5
5. Repeat steps 1-4 until TA is within the target range

?

With a 34,000 gallon pool, pH >8 and TA of 350....Yep!

Just remember, this is going to take a long time. Not a few days.

 

[kma_97]

Thank you, everyone! I will be patient, order the kit and try to get pH just a tad below 8 in the meantime. Then I should be able to use the new kit.

 

[PoolStored]

When you order a kit, get a smart stir. Very few things I have bought have been game changers. Speed stir is one. Makes the results super accurate by ensuring the chemical reactions during testing are consistent. You won't be disappointed.

 

[Katygreys]

If I dropped my smartstir and it broke when I was rigging up to test, I’d order another one immediately without question and after I ordered a new one, I’d finish doing my testing

Will you look like a geek? Yes. Will it be glorious? YESSS!!!

 

[Toxophilite]

That's not really answering my question and Pool Math does not tell how much can be added at one time...

1. Assuming I had said test kit and it produced the same results as posted in my original question, I am not asking "should I add all 167 fl oz at one once", but:
   "What is the maximum that can be added at one time (assuming results are produced by the recommended test kit and the target is still 167 fl oz)"?
2. Can I, without damaging the pool or equipment:
   1. Add 55 fl oz (mixed with a 3/4 of a 5 Gal bucket of water) in front of 3 return jets
   2. Run the pump for 30 min
   3. Test
   4. If pH <=7.2 or TA is within the target range, abort until pH is >= 7.5
   5. Repeat steps 1-4 until TA is within the target range

?

Many of us have had to deal with initial high TA and with high TA fill water. Just offering some insight to the process of dealing with it.

 

[kma_97]

When you order a kit, get a smart stir. Very few things I have bought have been game changers. Speed stir is one. Makes the results super accurate by ensuring the chemical reactions during testing are consistent. You won't be disappointed.

Looked at the kits. Recommendations? Smart stir (magnetic) is included with both "TF-Pro" and "TF-Pro salt". I have a salt pool with a SWG, so I am guessing "TF-Pro salt" is the right kit for me, yes? Not an overkill? Do I need optional "Salt Test Strips - Taylor" and/or "pH Meter"? Anything else I've missed?

Thank you!

 

[PoolStored]

Looked at the kits. Recommendations? Smart stir (magnetic) is included with both "TF-Pro" and "TF-Pro salt". I have a salt pool with a SWG, so I am guessing "TF-Pro salt" is the right kit for me, yes?

Yep.

Not an overkill?

Nope.

Do I need optional "Salt Test Strips - Taylor"

Nope.

and/or "pH Meter"?

I find the FAS-DPD FC test, included with the Pro kit super easy to use. The pH meter needs to be calibrated on an ongoing basis. Skip it.

Anything else I've missed?

Nope.

Thank you!

You are Welcome.

 

[proavia]

TFPro Salt will serve you well since you have a SWG.
Comes with the SmartStir.

You don't need the salt test strips as the TFPro Salt includes the salt test.
The pH meter may be nice to have, but for me its easier to just use the PH drop test.

 

[kma_97]

Thank you, again!

 

[Nikilyn]

I don’t remember reading that you can only drop it .4 at a time. I add what PoolMath tells me to. Sometimes it was 70oz. I was having a very difficult time getting my TA to drop. It was very frustrating. I found I wasn’t dropping my ph low enough. I was going to 7.2 and then not dropping it again fast enough. I decided to drop it to 7.0 because of a recommendation on here and dropped it again when it hit 7.6 (or 7.5, whichever is on the test). It dropped my TA in less than 2 days. I kept my waterfall on most of the time. So try getting the ph lower to begin with and not let it get too high.
I thought it was half an hour for chemicals to be fully mixed on high speed.