Is it true when adding acid only do 500ml max at one time? How long between additions? Got a high TA and want to reduce asap. Cheers
Adding acid
- Thread starter AussieSwimmer
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yann
0
- Aug 15, 2017
- 273
- Pool Size
- 36500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral VX 7T
The best way to reduce your TA is to drop your PH to 7.0-7.2 then aerate until your PH is back up again to 7.8-8.0, then start over again until you reach your target TA.
For most pools, 500ml of MA will drop PH from 7.8 to 7.2
Your pool is smaller than mine so unless your TA really high, I doubt you’ll need more than 500ml of MA at a time. Use pool math to calculate how much MA you need. If it’s more than 500 then add 500ml and re test your PH at 30min then add again if needed.
There’s is no fast lane to reduce TA unless you’re prepared to damage your pool and equipment by adding a very large amount of MA at once and risk a very low PH.
What is your current TA and PH. It would be helpful to have a full test result posted.
Also how fast is your PH creeping up to 8.2? How often do you have to add MA?
You’ll probably realise you’re already adding maximum MA at a time. Only way to speed up the process is through aeration.
Eventually you’ll notice you need to add less and less MA and less frequently as your TA comes down, until you finally hit equilibrium, the sweet spot, where your TA and PH are in balance and few adjustments are needed.
My pool is at TA90 and my PH is steady at 7.6. Only adding 100ml once every 2 weeks or so.
For most pools, 500ml of MA will drop PH from 7.8 to 7.2
Your pool is smaller than mine so unless your TA really high, I doubt you’ll need more than 500ml of MA at a time. Use pool math to calculate how much MA you need. If it’s more than 500 then add 500ml and re test your PH at 30min then add again if needed.
There’s is no fast lane to reduce TA unless you’re prepared to damage your pool and equipment by adding a very large amount of MA at once and risk a very low PH.
What is your current TA and PH. It would be helpful to have a full test result posted.
Also how fast is your PH creeping up to 8.2? How often do you have to add MA?
You’ll probably realise you’re already adding maximum MA at a time. Only way to speed up the process is through aeration.
Eventually you’ll notice you need to add less and less MA and less frequently as your TA comes down, until you finally hit equilibrium, the sweet spot, where your TA and PH are in balance and few adjustments are needed.
My pool is at TA90 and my PH is steady at 7.6. Only adding 100ml once every 2 weeks or so.
Last edited:
TA is 250ppm....haven't checked PH yet as FC still high post slam ~12ppm... I've added 500ml of acid....should I let FC drop below 10 or can I just keep testing TA? Sounds like I need to check pH eh?
Thanks mate
Thanks mate
yann
0
- Aug 15, 2017
- 273
- Pool Size
- 36500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral VX 7T
Yes you need to wait until your FC gets below 10ppm to get a proper PH reading.
Throwing random amounts of MA in your pool without knowing your PH is risky.
But hey, it’s your pool...
Throwing random amounts of MA in your pool without knowing your PH is risky.
But hey, it’s your pool...
yann
0
- Aug 15, 2017
- 273
- Pool Size
- 36500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral VX 7T
I’ve quickly punched up some numbers in pool math.
Assuming your PH is 7.8. With a TA of 250 it would take about 2.5l of MA to drop your PH down to 7.0, so I guess you didn’t create much damage throwing those 500ml blindly in your pool.
Not sure what the experts have to say?
If it was me I would wait until FC is under 10, then add 500ml at a time, testing PH every 30 min then add again if needed.
According to pool math, 2.5l of MA will drop your TA by 42ppm so I would definitely test TA as well before each addition and enter the new value in pool math. And test TA with the standard resolution while your TA is so high to save on reagents. Switch to high sensitivity when your TA is closer to 100.
Assuming your PH is 7.8. With a TA of 250 it would take about 2.5l of MA to drop your PH down to 7.0, so I guess you didn’t create much damage throwing those 500ml blindly in your pool.
Not sure what the experts have to say?
If it was me I would wait until FC is under 10, then add 500ml at a time, testing PH every 30 min then add again if needed.
According to pool math, 2.5l of MA will drop your TA by 42ppm so I would definitely test TA as well before each addition and enter the new value in pool math. And test TA with the standard resolution while your TA is so high to save on reagents. Switch to high sensitivity when your TA is closer to 100.
yann
0
- Aug 15, 2017
- 273
- Pool Size
- 36500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral VX 7T
yann
0
- Aug 15, 2017
- 273
- Pool Size
- 36500
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral VX 7T
It wasn't blindly btw, I used the pool math app as well, hence why I was asking about adding large amounts of acid.
No I've got no idea...I was a lazy pool owner up until now...
Just tested FC at 9ppm and pH 7.8...I might let FC drop to 6 or 7 and redo pH before adding more acid.
No I've got no idea...I was a lazy pool owner up until now...
Just tested FC at 9ppm and pH 7.8...I might let FC drop to 6 or 7 and redo pH before adding more acid.
- Oct 25, 2015
- 5,197
- Pool Size
- 25000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-60 Plus
Aussie,
I see you're a new member, welcome aboard! I hope this site is as helpful to you as it has been for me over the past 3 years or so.
There's not really a maximum amount of MA to add at a time. Most of the posts I've seen from experts on this site recommend an amount that only changes pH a few tenths of a pH unit at a time. This is due to the calculation methods limitations. They are not reliable over a very wide range. Typically they seem to prefer a change that is about .3 pH units at a time. Also as one answer above already noted please do make sure your FC is below 10 as pH test results above FC 10 are unreliable. Please also remember the pH test does not show pH greater than 8.2. So you can have 8.5 and it will look the same as 8.2. I have great difficulty reading the shades of red close to 8.2 (slightly color-blind in this range) so I've found it is much easier to do the pH test with a white background. If you hold the tester up to the sky make sure you have a white cloud behind it or better yet have a white paper background.
I hope this helps and good luck on your TA. Reducing TA will definitely improve your pH control.
Chris
- Jul 21, 2013
- 53,111
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- 35000
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- Chlorine
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- Pentair Intellichlor IC-60
Don’t reduce TA just to get TA to a number. If your pH runs high then your TA will naturally come down as you lower your pH.
What is the pH and TA of your fill water? If you have high TA fill water it many be a losing battle.
What is the pH and TA of your fill water? If you have high TA fill water it many be a losing battle.
- May 23, 2015
- 24,472
- Pool Size
- 16000
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- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Doing comprehensive testing is always best but let’s assume that your FC is too high to make the pH test reliable. There are two things you can do -
1. Dilute your pool water sample with an equal amount of DISTILLED water (1:1 dilution). At high TA, the dilution will have almost no effect on pH but it will cut your FC by half allowing you to test pH.
2. Only add enough acid to drop your TA by 10ppm. That is where the TFP recommendation comes from - for most swimming pools, adding enough acid to go from a pH of 7.8 to 7.2 (or 7.0) typically corresponds to a TA drop of 10ppm and that is usually measurable on the TA test (1 drop of reagent equals 10ppm TA).
1. Dilute your pool water sample with an equal amount of DISTILLED water (1:1 dilution). At high TA, the dilution will have almost no effect on pH but it will cut your FC by half allowing you to test pH.
2. Only add enough acid to drop your TA by 10ppm. That is where the TFP recommendation comes from - for most swimming pools, adding enough acid to go from a pH of 7.8 to 7.2 (or 7.0) typically corresponds to a TA drop of 10ppm and that is usually measurable on the TA test (1 drop of reagent equals 10ppm TA).
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