To Reef Crystal or Regular Salt?

As my tank matures I am looking toward moving to a reef specific salt formula. So I began thinking about this a bit.  I understand that a lot of it will depend on my alk, Ca and Mg test results.  A little background:  The tank is 55 gallons with a 20 gallon sump.  Lots of live rock and about 10 fish. There are about 20 easy to raise coral, mostly zoas, a couple of lobos and some acans in the tank. I have begun to frag some of it off and have a nursery rack set up in the tank.  I do >10% water changes each week (we have a FOWLR too that is also 55 gallons so I mix 15 gallons of water and split it between the tanks). The reef tank is doing well, all zeros across the tests, pH is 8.2 to 8.4 consistantly and I have 0.03 PPM phosphates. I'm using the standard new-guy salt, Instant Ocean. I currently don't test Ca, Alk, or Mg, but realize that I will have to start soon.

I hear many people using a salt mix that is designed for reefs. I also hear of a lot of people dosing.  My question is do I change to a reef salt and start dosing (once the test results show it's needed) or do I stay with the standard salt, do the water changes and dose as needed?  I'm having a hard time understanding the purpose of a reef salt if you're dosing anyway.

Thanks,
Fat

Do your research on reef crystals and the problems associated with it. I would also say there are better salts then others depending on your targeted goal. 

That all depends on the demand of your aquarium, testing would be the only way to know that.

Im using Red Sea Coral Pro salt, i dont have tons of corals to demand lots CA but so far just doing my monthly water change had kept my CA and Alk levels up. I do have to test and add mag/iodine from time to time.