Hi.
Magnesium (Mg), Calcium (Ca), and Alkalinity (Kh/Alk) is a must when having stonycorals + those mentioned above.
Then there s a wide range of others like Silica,
Phosphate, Strontium a.s.o. I only use these if something seems to be wrong with the corals, like
RTN or
bleaching.
Im using Salifert brand tests and they have worked fine for me.
