How much muriatic acid can be added at one time?

[setsailsoon]

So once again we added 24 oz of MA mixed it in with the pool brush and checked it 2 hours later and still the same ph reading which is around 8.2. I really do not understand how 24 oz MA in a 5000 gallon pool does nothing at all. Makes no sense to me. On Saturday when we are home all day we plan to add 16 oz and test every 2 hours then keep adding every 2 hours if the test does not show the desired ph. If that doesn't work I don't know what to do.

If the pH test reagents are good this could be a weakness of the pH test. When you have pH over 8.2 the test doesn't change color very much so your pH could be well above 8.2 and the pH is changing and you just can't detect it yet.. A friend of mine had this problem when he accidentally dumped a bunch of caustic soda into the pool. pH went through the roof. Digital pH testers are available under $20 and they will measure much higher. He didn't have one so we took out 2 gal of pool water in a bucket and added small amounts of acid, stirred, then tested pH. Didn't take much acid at all for a 2 gal sample but we ratioed up to calculate the amount of acid required. Then we added 25% of the calculated amount so we didn't overshoot. It only took about 3/4 of the calculated amount. As Matt mentioned above pH should be adjusted a small amount at a time due to the accuracy range of the calculations. Anyway we got the pool in great shape over 12 hours. pH seemed to go up quickly for a while but it got to normal operation in a couple of weeks. I should caution that doing this method requires handling MA many times and at close range. We both have a LOT of experience working in chemistry labs so we handled it very carefully. It's very easy to splash a drop in your eye so safety glasses with side shields are a must and set this up on a bench so comfortable to work on so you won't trip while working. If' you're not comfortable with this get a digital pH meter.

This does beg the question why not use a digital meter all the time? Answer is they're a pain. You have to calculate them often and the electrodes on cheap ones don't last too long.

Sorry for the long post and I hope it's helpful.

Chris

 

[YippeeSkippy]

I was just thinking what Marty said above but he beat me to it (as always, lol!). Which reagent number are you using, and you are adding 5 drops of that to the right hand column....correct?? One size comparator block uses R-0003 reagent, a different block size uses R-0014. Both are phenol red but they're not interchangeable.

Can you take a pic and share it of the test comparator block thingie so we can see it too? Preferably as you just finish the test and can show it in light with a piece of paper behind it or anything to help us see it.

 

[aussieta]

how much ma would you guess you have used in the last few weeks

 

[Rachelmarie]

I am concerned about your pH test. What is the code on the bottle. How old is it?

Its brand new and I have confirmed what I saw at home by the pool store a few times in the past couple weeks.

 

[Rachelmarie]

It says phenol red indicator solution for ph test. Yes I am adding 5 drops to the right side. We have had a pool prior to this one for 10 years so we know what we are doing which is why we are so confused because we have never experienced this before.

We had quite a bit of rain this morning so I am hoping that helped. I will be testing again in a couple hours since the rain has stopped.

As for how much MA in the past few weeks I do not know exactly but a lot. For the past 10 days we have been adding anywhere from 16-24 oz a day. And before that we were adding at least 8 oz every few days.

 

[Rachelmarie]

If the pH test reagents are good this could be a weakness of the pH test. When you have pH over 8.2 the test doesn't change color very much so your pH could be well above 8.2 and the pH is changing and you just can't detect it yet.. A friend of mine had this problem when he accidentally dumped a bunch of caustic soda into the pool. pH went through the roof. Digital pH testers are available under $20 and they will measure much higher. He didn't have one so we took out 2 gal of pool water in a bucket and added small amounts of acid, stirred, then tested pH. Didn't take much acid at all for a 2 gal sample but we ratioed up to calculate the amount of acid required. Then we added 25% of the calculated amount so we didn't overshoot. It only took about 3/4 of the calculated amount. As Matt mentioned above pH should be adjusted a small amount at a time due to the accuracy range of the calculations. Anyway we got the pool in great shape over 12 hours. pH seemed to go up quickly for a while but it got to normal operation in a couple of weeks. I should caution that doing this method requires handling MA many times and at close range. We both have a LOT of experience working in chemistry labs so we handled it very carefully. It's very easy to splash a drop in your eye so safety glasses with side shields are a must and set this up on a bench so comfortable to work on so you won't trip while working. If' you're not comfortable with this get a digital pH meter.

This does beg the question why not use a digital meter all the time? Answer is they're a pain. You have to calculate them often and the electrodes on cheap ones don't last too long.

Sorry for the long post and I hope it's helpful.

Chris

I have wondered if this was possibly what was going on. If this is the case I do not understand how it got so out of control when we have been adding acid on a regular basis from the beginning. My husband handles the MA I do not mess with it. I will tell him about this method and see if he wants to try. At the very least when we are home all day on Saturday we were going to try adding 16 oz then testing 2 hours later then adding more as needed and doing this all day until we get to where we need to be.

 

[mknauss]

With your most recent data (TA of 120) each time you add 16 oz of MA you are dropping TA by 12 ppm and pH should drop 0.8 points, if you are using 31.45% Muriatic Acid. Can you confirm that is the product you are using?

Be careful in repeatedly adding MA without monitoring TA. You must use a current TA in PoolMath to determine how much MA to use to drop pH. Are you using PoolMath to determine your MA amount to add?

 

[Rachelmarie]

With your most recent data (TA of 120) each time you add 16 oz of MA you are dropping TA by 12 ppm and pH should drop 0.8 points, if you are using 31.45% Muriatic Acid. Can you confirm that is the product you are using?

Be careful in repeatedly adding MA without monitoring TA. You must use a current TA in PoolMath to determine how much MA to use to drop pH. Are you using PoolMath to determine your MA amount to add?

Yes that is strength of our MA. At the moment the only way I can test for TA is at the pool store because I only have a PH and chlorine test. Which is the best test kit I can order that is the most cost effective? Since I am the one dealing with the testing I am just going to go ahead and order a better test kit, I am sick of guessing or having to go to the pool store for other results.

 

[mknauss]

Order a TF100 test kit
The only other real option for a test kit is a Taylor K-2006-C. Be careful comparing prices because the K-2006 comes in sizes, designated by a letter. The basic K-2006 has .75oz bottles. You need to get the K-2006-C to get the larger bottles that you want.
I also have the SpeedStir. It makes testing much easier.

 

[setsailsoon]

Order a TF100 test kit
The only other real option for a test kit is a Taylor K-2006-C. Be careful comparing prices because the K-2006 comes in sizes, designated by a letter. The basic K-2006 has .75oz bottles. You need to get the K-2006-C to get the larger bottles that you want.
I also have the SpeedStir. It makes testing much easier.

Ditto Marty's recommendation for the TF-100. I bought mine several years ago when I was trying to learn TFP. It was great because there is enough reagent to run lots of extra CYA tests... I kind of got carried away and was running all the tests every day for a few weeks. Also, the manufacturer really offers great support. I had a problem with one of the bottle tips. They were very responsive and fixed the problem immediately. Also, I could tell they were getting information from me to go back to suppliers and fix any potential systemic problems with their supply chain. Very refreshing! Lastly, they sell refill kits a couple of times per year at a good discount.

I hope this helps.

Chris

 

[scdaren]

Something very odd is happening for your pH not to go down. That's massive amounts of acid. You NEED to get a proper test kit asap to get this figured out. I would stop adding acid until you do that. Are you adding anything else to the pool aside from liquid chlorine and muriatic acid?

Also, you mentioned chlorine was up to 20 and you had to add something to lower it -- what did you add? An FC of 20 at CYA of 60 actually won't cause you any problems, you can let it come down on its own, even if it takes awhile. That being said, pool store CYA tests are more often wrong than right.

My pool was built last year and the pH always wants to rise. I've found that a TA of around 70 helps a lot. That will also lower your CSI so that you can be at a 8.0 pH and still be ok, at least in the winter.

 

[ajw22]

Note that pH tests are not accurate when FC is over 10. You need to get a full test kit like described above and look at all your water chemistry together and not your pH issue in isolation.

 

[Rachelmarie]

Ok so my chlorine was 1 on Monday so I turned it up from 10% to 15% and have not tested it since then because it was so low. I have just been looking at ph the past few days. I took a sample to the pool store because I felt like something had to be off. He told me my chlorine was up to 10 and that my pH was actually okay it was showing 7.6. I was confused as to how my chlorine from 1 to 10 when I only increased the production from 10% to 15% but then I realized when we added acid one evening and I turned the pump on for a couple of hours I forgot to turn it off and it ran all night so it basically ran 24 hours so I'm thinking that is why the chlorine is so high. Does that make sense?

Because the chlorine is at a level 10 that would make sense why my pH wasn't appearing to go down. That explains the recent issue doesn't explain why I've had to dump 2 to 3 cups of acid and daily for the past 10 days you would think my pH would have been a lot lower than 7.6.

I am happy its finally down but now I need to figure out how to get an accurate ph reading due to high chlorine. With the TF-100 kit will it show an accurate ph if chlorine is at 10? I am going to go ahead and order the kit today.

And to answer the question as to what we put in the pool to lower the chlorine it was a yellow algae killer. The guy at the pool store recommended it and gave me a free bag. It did the trick and brought it down from 20 to 1.

 

[ajw22]

None of the drop test kits will accurately test pH when CL is over 10.

Look at PH Meters if your going to have FC consistently over 10. Or let your CL drift back down.

 

[Rachelmarie]

None of the drop test kits will accurately test pH when CL is over 10.

Look at PH Meters if your going to have FC consistently over 10. Or let your CL drift back down.

Is there any other way to get chlorine down other than turning off the percentage to zero? I tried that last time and it did nothing after a few days so that'swhen we added the yellow algae killer. We get zero sunlight on our pool this time of year and the water has been cold which makes the chlorine stick around.

 

[ajw22]

Is there any other way to get chlorine down other than turning off the percentage to zero? I tried that last time and it did nothing after a few days so that'swhen we added the yellow algae killer. We get zero sunlight on our pool this time of year and the water has been cold which makes the chlorine stick around.

No. Turn your SWG down to its minimum % output or off and be patient. The FC will drop in-time.

 

[mknauss]

Do not add the stuff the pool store gave you. Most yellow algae ‘killers’ are bromide or ammonia. You want neither of those in your pool water.

 

[YippeeSkippy]

You had a pool for 10 years. You say you know what you are doing, yet you continue to use a pool store with its questionable advice and questionable testing and yet you're *still* having problems??

I don't understand resistance to buying a test kit and learning how to use it properly but having no problem buying a product like Yellow Out (or whatever it was called) and tossing that in the water. If that is bromine and you used enough of it you'd have changed your entire chemistry of the water and now own a bromine pool and not a chlorine one.

For a spool that size, have you consider a full drain and refill? It surely can't take too long or be too costly to fill up 5k gallons.

Maddie

 

[Rachelmarie]

You had a pool for 10 years. You say you know what you are doing, yet you continue to use a pool store with its questionable advice and questionable testing and yet you're *still* having problems??

I don't understand resistance to buying a test kit and learning how to use it properly but having no problem buying a product like Yellow Out (or whatever it was called) and tossing that in the water. If that is bromine and you used enough of it you'd have changed your entire chemistry of the water and now own a bromine pool and not a chlorine one.

For a spool that size, have you consider a full drain and refill? It surely can't take too long or be too costly to fill up 5k gallons.

Maddie

I guess what I was trying to say was we managed our pool fine and after 10 years it was still in good condition. Maybe we got lucky before. That is why we are hesitant to change what we do. I did not necessarily want to spend time checking several different chemicals. We used to weekly check ph and chlorine then monthly get a more detailed test done at the pool store.

I think that stuff was bromine, does that mean we will have issues? What does bromine do to a pool and how long will it take to go away?

 

[ajw22]

I guess what I was trying to say was we managed our pool fine and after 10 years it was still in good condition. Maybe we got lucky before. That is why we are hesitant to change what we do. I did not necessarily want to spend time checking several different chemicals. We used to weekly check ph and chlorine then monthly get a more detailed test done at the pool store.

The amount and type of care a pool requires partly depends on its environment. The TFPC methods work in even the toughest environments.

This isn’t about luck. You need to adjust your methods for your new pool environment.