Why Not make PPM the Standard For Alkalinity ?

[Scrubber_steve]

Doesn’t the Hanna Alkalinity checker give a reading in ppm

dkh

 

[Mortie31]

dkh

I must have an old one then... it gives me a reading of say 128 I then have to divide that number by 0.056 to get a dkh of 7.2

 

[CJS80]

Hanna has both. HI772 is in DKH, HI755 is in PPM.

 

[Scrubber_steve]

I must have an old one then... it gives me a reading of say 128 I then have to divide that number by 0.056 to get a dkh of 7.2

Well Mortie there are three to choose from, & Hanna can't make up their mind

 

[CJS80]

But two others that are measured regularly, cal 420ppm & magnesium 1250ppm to 1350ppm

Meq/L and mmol/L are the only other ways you hear these 2 represented, and as a non-scientist "imperialist" it seems to awkward.

 

[Mortie31]

Well Mortie there are three to choose from, & Hanna can't make up their mind

Tbh it doesn’t matter to me as long as my measurements are stable...

 

[Scrubber_steve]

Meq/L and mmol/L are the only other ways you hear these 2 represented, and as a non-scientist "imperialist" it seems to awkward.

yes, I feel that for aquarium purposes its simpler, & it only needs to be simple. The proposition seems slighting annoying for the pros though?

 

[Scrubber_steve]

just to be sure kh test is the same as an alkalinity test ??

 

[Dan_P]

Every other measurement is reported as ppm.
NH3/4
NO2
NO3
PO4
Calcium
Magnesium
Potassium
etc
Only alkalinity is reported in two other ways, meq/L & dKH.
130ppm to 200ppm. Easy

In this hobby, the average aquarist has no use for these numbers beyond ensuring that the ones they obtain with their test kits are within certain ranges. The units are irrelevant. When we reboot units of measure, molarity (we would mostly use millimolar or micromolar) might be the optimum unit to move to.

 

[Scrubber_steve]

In this hobby, the average aquarist has no use for these numbers beyond ensuring that the ones they obtain with their test kits are within certain ranges. The units are irrelevant.

Yes, but deciding on just one unit of measurement & sticking to it is my point.

 

[sghera64]

Doesn’t the Hanna Alkalinity checker give a reading in ppm

Yes - the older ones do. That’s what I have and my mind is now adjusted to PPM CaCO3.

 

[cpschult]

For those interested, I compare and discuss nearly all of the units of measure that reefers use here:

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

here's the mentioned entry for ppm calcium carbonate equivalents, which actually is used as a unit for alkalinity (Steve wants this) calcium, magnesium, and total hardness.

ppm calcium carbonate equivalents

ppm calcium carbonate (CaCO3) equivalents is an ambiguous unit used for a variety of measures by reef aquarists, including alkalinity, calcium, magnesium and total hardness. In the case of alkalinity and calcium, the unit refers to the amount (in ppm) of calcium carbonate that would have to dissolve into pure water to give the same calcium concentration or alkalinity (even if that would be impossible to accomplish). For calcium, 1000 ppm calcium carbonate equivalents equals 400 ppm calcium ion. For alkalinity, 100 ppm calcium carbonate equivalents equals 2 meq/L or 5.6 dKH. In the case of magnesium, the concentration refers to the amount of calcium carbonate that would have to dissolve to provide the same number of calcium ions as magnesium ions are present. For magnesium, 1000 ppm calcium carbonate equivalents equals 243 ppm magnesium ion. In the case of total hardness, the unit refers to the amount of calcium carbonate that would have to dissolve to provide the same number of calcium ions as the total of calcium and magnesium in solution. Using ppm calcium carbonate equivalents for magnesium and total hardness is poor practice as they are hard for most aquarists to understand, but they are used for historical reasons by certain testing companies (e.g., Hach, Figure 3). A calculator for converting between different alkalinity units is online here. A calculator for determining how much of different supplements to add to boost alkalinity, as well as calcium and magnesium, is online here.

That last link doesn’t work

 

[WillB]

Alkalinity is just a measurement of the level of bicarbonate & carbonate ions & the waters buffering capacity. The ratio of bicarb to carb ions is determined by pH. At 8.3 it it's totally bicarbonate. But it's the measuring system used to show its level I'm interested in here, & why we don't just all use the simplest one, ppm?

You lost me at “At 8.3 it it's totally bicarbonate” how how does the relationship change as you increase or decrease from 8.3?

 

[Scrubber_steve]

You lost me at “At 8.3 it it's totally bicarbonate” how how does the relationship change as you increase or decrease from 8.3?

 

[Randy Holmes-Farley Verified Community Expert]

yes, I feel that for aquarium purposes its simpler, & it only needs to be simple. The proposition seems slighting annoying for the pros though?

Seriously, why is ppm for alk "simpler" than meq/l? What is preferable about it?

One certainly cannot equate 100 ppm of alkalinity being somehow the same as 100 ppm of chloride. There's not anything in any context that is the same.

 

[Randy Holmes-Farley Verified Community Expert]

That last link doesn’t work

I think it does. Click the actual link (which is why I post it). The name of the article gets messed up with your old cookies and may not link properly.

 

[Scrubber_steve]

Seriously, why is ppm for alk "simpler" than meq/l? What is preferable about it?

1. As I said, "simpler" because everything else is reported this way, even salinity is in ppt
2. & you yourself quote it in ppm in your articles http://www.reefkeeping.com/issues/2004-05/rhf/index.htm so its use in the aquarium hobby is legitimate?
3. because i know that if i get a reading of 130ppm to 200ppm my alk is A ok. simple, simply "simpler" .

To ME, in the aquarium hobby /forums, its makes sense to have everyone report Alk in just one system rather than just randomly in one of three different standards - meq/L, dKH or ppm.
How difficult would it be, just for example, for others to help people if Cal, Mag, Potassium, chloride, sodium, strontium, NO2 & PO4 etc, were all continuously reported randomly in three different standards . . get out the calculator again to convert to the stated standard to the one I recognise ;Bookworm ;Blackeye ,,,, (nah, too much effort)
The consistent use of just either ONE of those three different measurements would be a positive, especially for newbies.

You pick meq/L & run with that & change the hobby for the better It can be done here at R2R. We have the power. We could start by making fun of others who don't conform to the selected standard. ;Jawdrop

 

[WillB]

Awesome! I had no idea! Thanks for taking the time to help me understand

 

[cpschult]

I think it does. Click the actual link (which is why I post it). The name of the article gets messed up with your old cookies and may not link properly.

https://my.xfinity.com/~jdieck1/chem_calc3.html Says sorry we cannot find this page, it has moved. "homecast" redirects me to this link.

 

[Scrubber_steve]

https://my.xfinity.com/~jdieck1/chem_calc3.html Says sorry we cannot find this page, it has moved. "homecast" redirects me to this link.

That link works fine for me.

Here's the bit about 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 {see my graphs above}).
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.

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