vitamins and water change

[i love fish]

if i do regular weekly water changes on my DT which is a FOWLR system, do i still need to test 4 Ca and Mg or is this only 4 if i have corals?

 

[mr_x]

only if you have corals.

 

[i love fish]

thank you

 

[ophiura]

I would keep on top of alkalinity, however, which is part of that mix. Even in a FOWLR, when your calcium, pH, Alk and Mg get out of wack, bad things can happen.