Ca/Mg/Alk levels

[BCOrchidGuy]

My question is simple, at least it should be but I know it's not... but it should be, anyway...

I don't want to go with a Ca reactor, I've got no room and it's just something I don't want to deal with.

So what Ca/Mg/Alk suppliments do people recommend. I'm looking at Purple up, B Ionic or C Balance. I used to use the RHF homemade Ca/Alk and dose Kent magnesium but am considering another way to keep my lvls up. Right now the tank is very light load as far as calcium demand, a few monti frags and two decent colonies and then a few tree corals, mushroom, riccordia and an LPS. I want to get a bunch of SPS frags over the next couple months though so the demand will increase.

Any thoughts or suggestions would be appreciated.

Douglas
ps the reason I am considering the Purple up, B Ionic and C Balance are they are complete so rather than having to dose different things I can do it all in one.