Once you have things dialed in--this takes pretty much daily testing at first--- then I tend to test weekly. When I test, I run Salifert Alk., Ca., Mg and No3. and then I use a Hanna meter for PO4. I also run carbon and GFO in separate reactors 24/7. WC's are less frequent than other folks at roughly 25% every 2 months. There is nothing wrong with more frequent WC's, I'm just lazy and have enough experience to know how far I can push it.
Daily dosing is B-ionic @ 300ML daily ( 240g. packed SPS tank) and Mg. as needed. I also add rather imprecisely--Potassium Iodide, strontium chloride which I don't test for and honestly can't say they do much for the corals, but I have always added these things and so I continue to do so. The iodide is certainly beneficial to my Chaeto growth. I have also been experimenting for the past few months with small additions of amino acids from Two Little Fishies and maybe, perhaps, could be, that it has helped coloration a bit.
I think the most important thing is to settle on a routine that seems to give the results you are looking for and stick with it. Constantly changing things up is the worst thing you can do. Observe your animals carefully and figure out the canaries in the coal mine that are clear tells that one thing or another is about to go amiss. IMO/IME far too many hobbyists strive for perfect numbers and rely on fancy equipment and potions rather than learning what their animals are very clearly trying to "tell" them.
