Difference between Baume and Percent

denniswiseman

Bronze Supporter
Nov 27, 2014
235
United Kingdom
#1
Hi
I have Hydrochloric acid 36% and don't see a relation between it in Pool Maths. Should I just go with 29% and just put a bit less in or is there a formula to convert
I would also like to know the difference between Baume and Percent
 

Caco

Well-known member
#2
Hi, great question!! Didnt know myself so did some research

FYI there is a 34.6% Hydrochloric acid in poolmath. I assume that would be pretty close to what you have


Baume to percent
The °Baume scale is an old antiquated method of measurement of a chemicalsSpecific Gravity. It was devised a long time ago and is a scaling on a hydrometerwhich measures the Specific Gravity of solutions.To really make things confusing there are 2 ways of using this scale, one for liquidsthat are more dense than water and one for liquids less dense than water.
Liquids with lower S.G. than water, S.G = 140 / (°Bé + 130 )
Liquids with higher S.G. than water S.G = 145 / (145 – °Bé )
So, if you have the °Baume of a known chemical, you could calculate the S.G. Fromthis you can compare the S.G. of the particular chemical and see what the actual %concentration would be.

Example
20° Bé Sodium Hydroxide NaOHSG = 145 / ( 145 – Bé ) = 145 / ( 145 – 20 ) = 145 / 125 = 1.16
If you look at the data of Sodium Hydroxide you will see that a S.G of 1.16 representsa concentration of approx. 15 %



 
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denniswiseman

Bronze Supporter
Nov 27, 2014
235
United Kingdom
#3
Thanks for the answer but the 34.6% Is for 22 Baume, is that the same as 34.6%, if so I'll go with that
I'm still confused with the answer of the difference between them. I won't bother if 34.6% is ok



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Caco

Well-known member
#4
I would use the 34.6% in poolmath, but being aware that your acid is 36%, so a little stronger
To try it measure the pool ph, use the 34.6% in poolmath to calculate how much you need, use that volume and then retest your pool ph about an hour later to see where you got to

I wouldn't worry about the baume. All it is is the measure of the density of the acid.
 

Caco

Well-known member
#6
If you are running your pump then your pool should be mixed well enough to test once an hour is gone past

Testing your ph before and after you add the acid is just so you can see what the effect was
If you wanted to drop your ph from 7.8 to 7.2, and because your acid is a little stronger it dropped down to 7.0 it would be good to know that
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
10,885
Bedford, TX
#7
That is what I'm doing as I'm reducing my TA and aerating to bring the pH back up
Is an hour long enough?
I also brushed as well


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Dennis,

Not sure how much aeration you have, but it takes me about two days of adding acid, aerating, testing, etc over and over to reduce my TA from about 90 to below 70..

I'm using about a four foot waterfall for aeration.

Jim R.
 
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denniswiseman

Bronze Supporter
Nov 27, 2014
235
United Kingdom
#8
Thanks for all the info
After aerating overnight to 7.8 I added acid this morning to bring it down to 7.4. My TA is now 100 and I think I shall leave it like that for the time being
I use a large pond aerator with 4 giant air stones with an air yield of 6000 litres per hour.