Units of Measurement for Water Quality

[flanque]

Hi,

What are the different units of measurement for the following?

Ammonia
Nitrite
Nitrate
Phosphate
Specific Gravity
pH
Hardness ([acronym:92896a6750="Carbonate Hardness"]KH[/acronym:92896a6750])
Calcium


Thanks. Oh, is there a way to convert between all of these?

Ammonia, NitrIte, and NitrAte are all in [acronym:92495d573c="Parts per Million"]ppm[/acronym:92495d573c] pH is how condensed are the hydrogen molecules and i dont know the rest all i know is [acronym:92495d573c="Freshwater"]FW[/acronym:92495d573c] im not a salty

[flanque]

Yeah but you can represent things like [acronym:3c30e78cf1="Calcium"]CA[/acronym:3c30e78cf1] in dKH for instance. I would like to know all the different measurement units for the elements above.

[Toirtis]

[acronym:21cbc335b7="Parts per Million"]ppm[/acronym:21cbc335b7], ml/L, [acronym:21cbc335b7="milligrams or magnesium, depending on context"]mg[/acronym:21cbc335b7]/L...thats about it.

[jsoong]

pH = -log[H+] ..... [H+] is the concentration of hydrogen ions (= protons) measured in Eq/l (that's equivalents <number of charge, or in H+ = number of molecules> per liter) .... pH itself has no units.

[acronym:04c055d37f="Carbonate Hardness"]KH[/acronym:04c055d37f] is a measurment of the [acronym:04c055d37f="Hydrogen carbonate"]HCO3[/acronym:04c055d37f] & [acronym:04c055d37f="Carbonate"]CO3[/acronym:04c055d37f] concentration ... this is measured in [acronym:04c055d37f="milligrams or magnesium, depending on context"]mg[/acronym:04c055d37f]/l <milligrams per liters> which is the same as [acronym:04c055d37f="Parts per Million"]ppm[/acronym:04c055d37f]. [acronym:04c055d37f="Carbonate Hardness"]KH[/acronym:04c055d37f] is also measured in degrees hardness (dH) -- 1mg/l = 0.056 dH. Note that the dH is US measure, there is also German degrees & grains (British?) hardness. You can also convert [acronym:04c055d37f="Parts per Million"]ppm[/acronym:04c055d37f] to mEq/l. For [acronym:04c055d37f="Calcium carbonate"]CaCO3[/acronym:04c055d37f], 1mg/l = 0.02 mEq/l.

Picky technical note - typical [acronym:04c055d37f="Carbonate Hardness"]KH[/acronym:04c055d37f] kits do not measure [acronym:04c055d37f="Carbonate Hardness"]KH[/acronym:04c055d37f]! The kits actually measures total alkalinity, although the unit is expressed as the equivalent [acronym:04c055d37f="Carbonate Hardness"]KH[/acronym:04c055d37f]. (ie dKH)

[acronym:04c055d37f="Ammonia"]NH3[/acronym:04c055d37f], [acronym:04c055d37f="Nitrite"]NO2[/acronym:04c055d37f], [acronym:04c055d37f="Nitrate"]NO3[/acronym:04c055d37f], [acronym:04c055d37f="Phosphate"]PO4[/acronym:04c055d37f], [acronym:04c055d37f="Calcium"]Ca[/acronym:04c055d37f], [acronym:04c055d37f="Iron"]Fe[/acronym:04c055d37f] are all measured in [acronym:04c055d37f="milligrams or magnesium, depending on context"]mg[/acronym:04c055d37f]/l (=[acronym:04c055d37f="Parts per Million"]ppm[/acronym:04c055d37f]). You can covert to mEq/l by dividing [acronym:04c055d37f="Parts per Million"]ppm[/acronym:04c055d37f] by the respective molecular weight then multiply by the number of charge of the molecule.

Specific gravity has no unit. This is a measure of density as a ratio to pure water.

Water's density = 1g/ml or 1Kg/l

if you add (say) 10 g of salt to 1l of water, the density of that salt water is (1000g + 10 g)/l or 1.010 Kg/l.

specific gravity = density of salt water /density of water ....

in this example [acronym:04c055d37f="Specific gravity"]sg[/acronym:04c055d37f] = 1.010 Kg/l / 1.000 Kg/l = 1.010 .....

ie. to get specific gravity, you just calculate the density in Kg/l & drop the units!