Rookie dosing questions...

[Matt]

You need to be introduced to the greatness that is Randy Holmes-Farley. Many of his excellent articles from ReefCentral are linked on the Reef Chemistry page right here: http://www.canreef.com/vbulletin/forumdisplay.php?f=41

In short, Kalk is a buffered solution already, with Ca and Alk in proportion. If you are dosing Ca directly, you'll need to add Alk too. Again, in addition to the commercially-prepared buffered and two-part additives available at your local shop, Randy's (yep, the same Randy) home brew two-part solution is recommended by loads of successful reefers. http://reefkeeping.com/issues/2006-02/rhf/index.php

Repeating the oft-quoted advice from many: Don't add anything you're not testing for.

As for your central question: should you be dosing... testing will tell. You'll have to bring your levels up, likely through a series of additive adjustments or water changes. Then maintenance according to uptake (use). Kalkwasser (limewater) is a fairly easy way to maintain levels for many people (including the aforementioned guru, Randy, who recommends it).

Last tip: if you decide to make your own two-part, or dose Kalk, look at LittleSilverMax's vendor forum here. Great prices for quality ingredients.