In What Unit Do You Measure Alkalinity?

[Nick Kohrn]

I am building an application for tracking water parameters, and I am curious as to in what parameter you use most to measure alkalinity. I usually see measurements in dKH, but there is also meq/L and ppm CaCO3.

I am trying to figure out how popular these units of measurement are so that I know whether I need to implement the conversions.

Thanks for your time and help!

 

[DeniseAndy]

As long as you know consistently what you measure in it does not really matter. I personally use a Hanna checker, so it measures and I convert to meq/L so mine is usually 2.7 to 3.0. Easier to convert on the fly.

 

[Labridaedicted]

I use dkh, myself

 

[sawdonkey]

I use ppm because that is what my Hannah spits out.

 

[Nick Kohrn]

Thanks for your responses! It looks like I will be adding all three units. I appreciate your help!

 

[Elementalj]

+1 dKH

 

[Salty1962]

dkh

 

[Randy Holmes-Farley Verified Community Expert]

Moat hobby people use dKH, but it is easier to interpret meq/L in a chemical sense.

 

[Nick Kohrn]

As long as you know consistently what you measure in it does not really matter. I personally use a Hanna checker, so it measures and I convert to meq/L so mine is usually 2.7 to 3.0. Easier to convert on the fly.

What equation are you using to convert units? I was under the assumption that 1 meq/L == 1 ppm.

 

[DeniseAndy]

The Hanna checker gives ppm I believe and you convert this by multiplying the number by .02 or for DKH you multiply by .065 or .056 cannot remember. It has been so long since I used that one.

 

[CodyRVA]

I would be less concerned with units and more concerned with stability, but +1 DkH. As an app designer myself, I would make the unit dynamic per the users specific choice/preference.

 

[120reefkeeper]

I prefer DKH just my personal preference.

 

[Randy Holmes-Farley Verified Community Expert]

What equation are you using to convert units? I was under the assumption that 1 meq/L == 1 ppm.

1 meq/L = 2.8 dKH = 50 ppm calcium carbonate equivalents

This has all you would likely want to know about units:

The Units of Measure of Reefkeeping by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2005-08/rhf/index.php

from it:

Alkalinity

Alkalinity is a measure of the amount of acid necessary to reduce water's pH to the point where all carbonate and bicarbonate have been converted into carbonic acid (about pH 4.2 in seawater). In seawater, bicarbonate and carbonate provide nearly all of the alkalinity. Consequently, reef aquarists can use it as a surrogate measure for bicarbonate and carbonate which are taken up by calcifying organisms (Figure 1). The units of alkalinity can be meq/L (milliequivalents per liter), dKH (degrees of carbonate hardness), or ppm (meaning ppm of calcium carbonate equivalents). One meq/L = 2.8 dKH = 50 ppm CaCO3 equivalents. Seawater has an alkalinity of about 2.5 meq/L = 7 dKH = 125 ppm CaCO3 equivalents.

Alkalinity is not a measure of pH, although some people talk of it that way, nor is it a very useful indicator of a solution's buffering capacity, although it is related strongly to buffering capacity. An article explaining in detail what alkalinity is and what its units mean is online here. There is a calculator for converting between different alkalinity units online here. Here is an online calculator for determining how much of different supplements to add to boost alkalinity, as well as calcium and magnesium.

 

[DereksReef77]

DKH

 

[Nick Kohrn]

1 meq/L = 2.8 dKH = 50 ppm calcium carbonate equivalents

This has all you would likely want to know about units:

The Units of Measure of Reefkeeping by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2005-08/rhf/index.php

from it:

Alkalinity

Alkalinity is a measure of the amount of acid necessary to reduce water's pH to the point where all carbonate and bicarbonate have been converted into carbonic acid (about pH 4.2 in seawater). In seawater, bicarbonate and carbonate provide nearly all of the alkalinity. Consequently, reef aquarists can use it as a surrogate measure for bicarbonate and carbonate which are taken up by calcifying organisms (Figure 1). The units of alkalinity can be meq/L (milliequivalents per liter), dKH (degrees of carbonate hardness), or ppm (meaning ppm of calcium carbonate equivalents). One meq/L = 2.8 dKH = 50 ppm CaCO3 equivalents. Seawater has an alkalinity of about 2.5 meq/L = 7 dKH = 125 ppm CaCO3 equivalents.

Alkalinity is not a measure of pH, although some people talk of it that way, nor is it a very useful indicator of a solution's buffering capacity, although it is related strongly to buffering capacity. An article explaining in detail what alkalinity is and what its units mean is online here. There is a calculator for converting between different alkalinity units online here. Here is an online calculator for determining how much of different supplements to add to boost alkalinity, as well as calcium and magnesium.

Thanks so much for that!

 

[revhtree Verified Admin]

DKH for me!

 

[LuckyEd]

dkh

 

[smh254]

Hanna ppm

 

[drernesto Verified Sponsor]

dKh for me, but you should follow Dr. Randy's methods

 

[Coralville]

Meq/l, but I know I'm in the minority