The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.
Adding Ca, will actually make your Alk level even lower...Bulk Reef Supply has a great 2-part formula( its actually 3), for Ca and Alk supplementation.
Once you get your levels to their respective proper places, you dose equal amounts of both mixes. One Ca, and one Alk. It also comes with a corresponding amount of Mag.
BRS TV has a video of how to do it all. It's really quite easy!