[GreenHorn]

Hi guys, is there an 'average' concentration of calcium carbonate in any given water sample? For example sea water or tap water, and if so, what is it? I've searched all over the net and can't find any figures for it...

[Dan]

The calcium carbonate level will vary from area to area. Eg, hard water and soft water areas in the UK. Have a look at this http://en.wikipedia.org/wiki/Hard_water#Types_of_measurement it has the concentration ranges for different water hardness. That may be of some help, as far as tap water's concerned.

[mir]

Hi guys, is there an 'average' concentration of calcium carbonate in any given water sample? For example sea water or tap water, and if so, what is it? I've searched all over the net and can't find any figures for it...

The science of environmental chemistry in water is called Limnology. A keyword is alkalinity and total inorganic carbon. You measure this by titration.
Try to look up the methods and models in R.G.Wetzels: "Limnology" 3.ed ISBN 0-12-744760-1

The hardness is largely governed by the content of Ca and Mg salts. Also the time of year, the pH, geology, the dissolved organic carbon (humic acids etc), productivity from plants and algea and weather have great impacts of distribution of CO2 - And finally have impact of the salt contents. This is a really fascinating and complex mechanism, no water system completely alike.