I was thinking about the bare minimum to keep a tank healthy, and boiled it down to measuring alkalinity and salinity, keeping salinity stable, and alkalinity correct with a balanced additive (alk/Ca/Mg), with regular water changes. Not for an SPS tank with huge consumption, but a softy/LPS tank with fish.
So what else do you think NEEDS to be tested, and why?
So what else do you think NEEDS to be tested, and why?