Alk question

[rick4him]

I have a nutrafin kh/gh test kit.

 

My KH is 150. How do I convert this to alk? The back of the manual says to X that number by .056 to get my Dh which would be 8.4. Is this the same as my alk? Is the 8.4 number within a good dh range?

[Asureef]

I have a nutrafin kh/gh test kit.

 

My KH is 150. How do I convert this to alk? The back of the manual says to X that number by .056 to get my Dh which would be 8.4. Is this the same as my alk? Is the 8.4 number within a good dh range?

 

http://www.saltyzoo.com/SaltyCalcs/AlkConv.php

[lakshwadeep]

Short answer: your alkalinity is in the normal range:

2.5 - 4 meq/L or 7 - 11 dKH or 125 - 200 ppm CaCO₃ equivalents

 

150 is likely in ppm CaCO₃ (parts per million calcium carbonate). What you're trying to find is dKH (degrees carbonate hardness), with one degree being equivalent to 17.848 ppm CaCO₃. You're conversion is correct (it's basically the same as 150÷17.848). As asureef's link indicates, there is a third unit used: meq/L (milliequivalent per liter), which can be found by dividing ppm CaCO₃ by 50. This link is a good description of alkalinity; section 9 "units of alkalinity" is a more thorough explanation of these units:

http://www.advancedaquarist.com/2002/2/chemistry