maybe those people have already determined the consumption rate and have comprehensive set of testkits?
are u supplementing strontium, iodide, mg too? r those really necessary ?? does your coral health decline becoz of the lack of them??? maybe other bro/sis can assist .. ive not kept SPS .. dont really see the need to suppement em .. infact i'll refrain from adding anything i cannot measure
i supplement my tank with alk/cal/iron which i dont really have testkits for .. i measure the intank by eyeing on the algae growth really...