All the same my friend. Carbonate hardness is the measure of alk. dKH is just a different way to state your alk. It refers to degrees of alk [1 degree equaling approximately 17.8mg/L] (KH is an abbreviation for the German word for carbonate hardness, I believe).
Anyway, it is all the same no matter how you slice it. To keep it up you would add bicarbonate of soda, otherwise known as good old Arm and Hammer baking soda. If you want to make it stronger then bake it in a Pyrex dish at 400 degrees for about 30-40 minutes, and you get the pure soda ash. Either way you will want to dilute it in your water change water or you can add it to your RODI top-off water. I don't know the size of your tank, amount of coraline algae, evaporation your tank experiences, and/or the amount and type of corals you have, so it would hard for me to recommend a dose per day. If you get into a lot of corals then you might want to look into a dosing pump to keep your levels up, but at that point you will probably be dosing more than just alk. Let me know if you get to that point. I have been around for a bit, but new to RC.:dance:
