Raise your specific gravity before you do anything as that will add calcium and alkalinity. Your specific gravity should be 1.026 for a reef. You should buy a magnesium test kit as well because it is the third part of the triangle, and you need to monitor its level just as much as your calcium and alkalinity. I would say you should take about a week to raise your levels up to the proper amounts, just add a little each day. Take what the calculator tells you to add, and add 1/6th everyday or even 1/10th everyday until they are good.
Take a red through the guide in my signature for more info.
