Alkalinity test result interpretation

[argo]

Randy, I have a question on Alkalinity test result interpretation.

I've recently purchased LaMotte's Alkalinity test kit (Model WAT-DR, Code 4491-DR).

The titration test result indicated 180 ppm of CaCO3. Now, to convert this to dH I used the following formula:

1.00 mg/L (CaCO3) = 0.056 dH
1.00 mg/L = 0.9756 ppm (salt water @ 1.025 sp), thus

180 ppm of CaCO3 = 175.608 ppm and
175.608 X 0.056 = 9.834 dH

I am doing this correctly?

Thank you for your help.

[Randy Holmes-Farley]

Yes, 180 ppm CaCO3 equivalents is about 10 dKH.

In this article that tells all about alkalinity, I describe the various conversions:

http://www.advancedaquarist.com/issues/feb2002/chemistry.htm

Additionally, this link gives a conversion table:

http://ozreef.org/reference/alkalinity_conversion.html