is sounds dismissive of chemistry am aware but what we're really doing is advocating direct physical action over precision seeking + water counter adjustments, those actually tend to hyperfocus and exclude the physical practice/cpr which always works.
tanks that upcycle white rocks are just heading towards gardening work for a while, and the physical side will always work best there and then of course some get lucky with animal arrangments that keep things clean anyway. you are safer running a bit too high of phosphate vs too low (dinos is bad) so not testing for it and instead feeding well, exporting well, really has a strong track record. better record than all phosphate detailing, Ill never need anything but temp and salinity as the only two meters I own to keep any coral that fits in my tank long term. my tank does not need to know ammonia, nitrite, nitrate, phosphate, mg, calcium alk or pH in order to grow copious sps and lps for fragging, its a well-fed system.
those params are still critical, but weekly water changes happen to balance em apparently. after six mos of work and a clean guided reef to show for it, more precision testing can let you back off water change work but its not needed up front and actually unhelpful in my opinion.