Alkalinity and Calcium Conversion Chart

[Sandworm]

We do get asked what the different test kit readings are in relation to dKH vs KH and PPM. So I have taken and made up a little chart that shows the those equivalencies and the relationship to Calcium level.

Alk meq/L Alk dKH Alk ppm CaCO3 Calcium ppm Ca++ Calcium ppm CaCO3
0.0----------0.0-------------0-------------------360------------------900
0.5----------1.4----------- 25-------------------370------------------925
1.0----------2.8------------50-------------------380------------------950
1.5----------4.2------------75-------------------390------------------975
2.0----------5.6-----------100------------------400------------------1000
2.5----------7.0-----------125------------------410------------------1025
3.0----------8.4-----------150------------------420------------------1050
3.5----------9.8-----------175------------------430------------------1075
4.0----------11.2----------200------------------440------------------1100
4.5----------12.6----------225------------------450------------------1125
5.0----------14.0----------250------------------460------------------1150
5.5----------15.4----------275------------------470------------------1175
6.0----------16.8----------300------------------480------------------1200
6.5----------18.2----------325------------------490------------------1225
7.0----------19.6----------350------------------500------------------1250

Thanks to Travis for his partial input on this.

Jim

[thomas1102]

hey my alk is 250-275ppm. how come my calcuium is onmly at 400???? is it because im only using a 1 part calcium supplement? i just got kent marines 2 part supplement, will this help?

[1996 cobra]

alk and calcium arent always in a direct relation. check your magnesium lvls. alot of time sea salts dont provide sufficient lvls of mag and will result in a lower calcium lvl. a liquid calcium as well as a good kwalk mix usually can substain heavy calcium draws. a calcium reactor or lime reactor are the easiest way to substain and maintain a calcium lvl of desired choice and are very low maintence.

justin

[Mike O'Brien]

this link has been helpful for me
http://saltyzoo.com/SaltyCalcs/AlkConv.php