Alk/Ca

[vjvl51]

From this article - http://www.advancedaquarist.com/issues/nov2002/chem.htm

"Alkalinity2 (due to bicarbonate and carbonate but not borate, so those using Seachem salt must raise this value substantially to accommodate the borate being counted in standard alkalinity tests)

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

Calcium:

380 – 450 ppm calcium ion or 950 - 1125 ppm CaCO3 equivalents"

Your readings look good. I try to get at the mid point of the above ranges. You also want to ensure that Ca & Alk are balanced. I use this calculator for that - http://www.kademani.com/reefchem.htm

Vickie