Water Chemistry

i really wasnt a big tester, but latley ive wondering why i cant keep certain Acros the oringinal color from when i purchased them, i found this nice article: http://reefbuilders.com/2008/09/03/g...-vivid-bright/ . So it got me thinking, i dose 2 part and test my cal and mag ocasionally same for nitrates(make sure bio pellets are working).So what else is missing? I had seen the Red Sea kits popping up on the internet, then i saw them at my LFS. Being a person ...