I'm one of those ostrich people (I keep my head buried in the sand
) If everything is going good then what I don't know won't hurt me. It's working so far and I do keep a very close eye on the animals to make sure nobody is off colour or unhappy
The only thing I've tested for in the last 6 months has been alk (If my alk drops I assume my cal is dropping too)
I've even given up testing Mg, If the coraline stops growing on the glass then I add a few cup fulls