calcium levels

I've been told that there is a salt that comes complete with calcium and Magnesium as well as many other goodies... What I was wondering is if that may be all I need to put into my tank. I haven't had any luck with the calcium test kits, and I'm trying to make life easier.

I just tested the water this morning and my results show.. PH 8.0 Ammon. 0 Nitrite 0 Nitrate 20ppm KH 9 phos. .5 Cal. 760!!! I buy saltwater from the lfs since I still need to get a RO system, I found this other place that had water straight from the ocean over here from Catalina Island...

ok ive got a 10 gallon with a couple of LR pieces, some snails, and hermits. i just set up the tank like 2-3 days ago and my levels are srewy nitrate: 10ppm calcium:20ppm (thats way to low right)the test tube turned blue on the first drop phosphate:0ppm

hey guys Im conducting a sort of small experiment.....I have put together a small 10 gallon tank with only the purpose of trying to get coraline to grow from two small live rocks to one larger "dead" rock. lighting: totally insufficient.......soon to be changed to single PC 20" 40w...