Consensus seems to be,
Hanna alk
Salifert Ca and MG
Red Sea NO3 and PO4 or
Hanna PO4(I have the Low Range, need the ULR)
I'll order up those. I did like the Red Sea Pro Alge kit with the NO3 and PO4, the Mg was really hard to read and Alk was impossible to get consistent color change.
I think the range has to big of a spread on the Red Sea NO3 so I use the pro kit. Guess it all depends on your level