Simple method of dosing alk?

[untamed]

I think the standard advice would be to add Alk supplement only until you achieved "balanced Ca/Alk"...What you consider to be balanced is maybe a bit subjective... Let's say it is around 400-440 Ca...and about 8-9DKH.

Once you have that, you should maintain it with a balanced additive (like A/B, Kalk, Ca Reactor). Then use this balanced additive to maintain these levels. A dropping Alk level serves largely as an indicator that you are not replacing BOTH...even though the Ca level appears to be holding.

To quote Holmes-Farley..."The "mechanism" arises in the simple fact that alkalinity rises and falls much faster than does calcium because seawater has a much bigger reservoir of calcium than it does alkalinity."

A good recommended read:
http://reefkeeping.com/issues/2004-12/rhf/index.php