 Where is my alkalinity going?
I have decided to start keeping sps corals and have had my frags now for a couple of months. I even rearranged my tank and changed out and added a couple of power heads. So, I have been testing my calcium and alkalinity levels weekly to make sure they are within my specs. I use Oceanic salt because it dissolves easy and it has high levels of calcium.
My Calcium was reading around 500 and my alkalinity about 2 meq/liter.
So, I adjusted my alkalinity up by adding baking soda to about 4 meq/l. A week later I did another test with the same results. So, another adjustment was made. A week later same results  Where is my alkalinity going? I know magnesium is supposed to help keep these guys mixed properly, So I guess I am going to have to do the PIA magnesium check. Cotton ball filtering and all, titrating for alkalinity is so much easier. Anyone have any ideas?
And don't ask my what my magnesium level is  I don't know yet but I am going to wander off and check it now  I have the Mag flake to add if I need it, thanks to one of our sponsors twopartsolutions.com Anyone have any ideas? 
Thanks,
Jim
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90 Gallon glass, 135#'s of rock and 2" sand. 2-250w 20k XM metal halides. 2-95 watt actinic VHO, 4 powerheads, Coralife skimmer. Maroon Gold Striped Clown, Blue Chromis, Kole Tang, Pygmy Angel, Serpent Star, Brittle Star,Gorgonians, Mushrooms, Yellow Polyps, Turbo Snails & Blue Legged Hermits. 20 gal sump with Caulerpa, Mag 7 return pump. | 
