Alk: Range 7-11 depends on your tanks need
Cal: Salifert test kits state 425 in a natural environment. Range 425-480 again depends on your tanks need.
Mag Range: Salifert states 1300-1500 in natural environent. Range again depends on your tanks need.
With that.. you may also have low PH or Slightly higher PH. Depends on your tank.
Make sure your Mag levels are straight 1st before you try and raise or lower anything.
Then work on the correct dosing regimine for your tank. I find the best way to do that is by using dosing pumps. Congrats on your decision... it's alot more challenging.
The levels are the same if you keep a softie, mixed, SPS or a mix of any of those. The only thing that changes is the importance of keeping each at those levels. Just a FYI.
Just a note. A Coal reefs pH can fluctuate as much as 0.25 pH units in 24 hrs and temp 2 C in 24 hrs. Salinty is much more seasonal. However, coral reefs are not reef tanks and stability is a better working theory.