1st off, sorry, redundant question.Check PH with HM TDS EZ meter

rtmike

rtmike

Member
I was using the little PH strips you get at the pet stores & I'm about out. I have a Hannah TDS EZ water meter that's still new from not using it.


This is NO bull but I've searched You Tube & the 'net for close to 2 hours. I give up. Apparently I'm not using the correct "search" words? I've edited words over & over here & other forums too trying to find an answer.

Please, may I ask how to convert the ppm number I get from the meter to check the PH...or can I?


Oh man. I tried every combination of the words trying to find a solution. It's a question I'm sure is asked dozens of times hence me not wanting to start a thread.

It's too bad that when you do a search it doesn't take you directly to the post or even page so you don't have to read through every single page. That's not a bad thing since I'm learning...but I have to give the girls some new refreshments before it gets dark here.

Thanks in advance!!!!!!!
 
S

stinkyjoe

Well-Known Member
rtmike said:
LOL, that would sure explain a lot. Thanks...for the answer anyways, lol.
Click to expand...
good question
ppm is usually a molar ratio: 1 mole substance per 1x106 moles of total solution.
mg/L (milligrams/liter) is more often used for liquid solutions
pH is related to the molar concentration of the H+ ion in a solution in moles/liter. The pH value is the negative logarithm of the moles H+ concentration in a liter of the solution.
So we have several interacting concentration, volume and mass measures in play.
Let's assume a pH of 5 as our test case.
This means there are 1x10-5 moles of H+ in one liter of the solution. At this low concentration the mass of the solution will not be much different fom water, so the solution has mass of 1000 grams or 1,000,000 milligrams.
H+ has a molar mass of 1 gram/mole or 0.00001 gram per 10-5 mole.
So a weight ppm value of the H+ ion in the solution is 10-5 g/liter (or 1 million milligrams). Converting g to mg we arrive at the answer that a pH contains 10-2 ppmw of H+.
However if the ppm is to indicate the ppm value of the acid contributing the H+ ions it is necessary to change the molar mass of H+ to the molar mass of the acid (you have to know what acid is present).
Using H2SO4 as an example, the molar mass is 98 g/mole and each mole
contributes 2 moles of H+ to the solution. There would be (98/2)x 10-5 ppmw (or (49x 10-5 ppmw)of H2SO4 in the solution
 
S

stinkyjoe

Well-Known Member
sorry forgot a bit

However if the ppm is to indicate the ppm value of the acid contributing the H+ ions it is necessary to change the molar mass of H+ to the molar mass of the acid (you have to know what acid is present).
 
707humboldt

707humboldt

Well-Known Member
rtmike said:
LOL, that would sure explain a lot. Thanks...for the answer anyways, lol.
Click to expand...
No problem dude, I personally use blue lab guardians in all my rooms. They do ph/ec,tds,ppm/temp all in one. Also have a connect feature that will send all this data to your computer for analysis. Totally worth it if you have a decent sized setup. If you just want a ph pen, blue lab makes a good one of these too. Just make sure to take care of it, clean it, calibrate it, store it properly, and it will last a long time. Definitely worth the investment to get accurate readings and be able to dial your system in perfect. The ph strips and drops work but they are vague and when you test nutrient water that has a tint to it, it can be hard to read the color accurately.

Just my .02
 
rtmike

rtmike

Member
stinkyjoe said:
good question
ppm is usually a molar ratio: 1 mole substance per 1x106 moles of total solution.
mg/L (milligrams/liter) is more often used for liquid solutions
pH is related to the molar concentration of the H+ ion in a solution in moles/liter. The pH value is the negative logarithm of the moles H+ concentration in a liter of the solution.
So we have several interacting concentration, volume and mass measures in play.
Let's assume a pH of 5 as our test case.
This means there are 1x10-5 moles of H+ in one liter of the solution. At this low concentration the mass of the solution will not be much different fom water, so the solution has mass of 1000 grams or 1,000,000 milligrams.
H+ has a molar mass of 1 gram/mole or 0.00001 gram per 10-5 mole.
So a weight ppm value of the H+ ion in the solution is 10-5 g/liter (or 1 million milligrams). Converting g to mg we arrive at the answer that a pH contains 10-2 ppmw of H+.
However if the ppm is to indicate the ppm value of the acid contributing the H+ ions it is necessary to change the molar mass of H+ to the molar mass of the acid (you have to know what acid is present).
Using H2SO4 as an example, the molar mass is 98 g/mole and each mole
contributes 2 moles of H+ to the solution. There would be (98/2)x 10-5 ppmw (or (49x 10-5 ppmw)of H2SO4 in the solution
Click to expand...



Thanks for that,Lol. wow.

I'm sorry man, you mean well but just cause I graduated high school doesn't mean there's ANY way I can comprehend even a little of that, lol. I now have a knot on the back of my head from that flowing over the top of my head, hitting the wall behind me & bounced back hitting smack dab in the back of the head. Thanks, he-he.
 
S

stinkyjoe

Well-Known Member
rtmike said:
Thanks for that,Lol. wow.

I'm sorry man, you mean well but just cause I graduated high school doesn't mean there's ANY way I can comprehend even a little of that, lol. I now have a knot on the back of my head from that flowing over the top of my head, hitting the wall behind me & bounced back hitting smack dab in the back of the head. Thanks, he-he.
Click to expand...
glad i could help :)
 
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