i don't have the data...
kept sps for years. i tried out vodka before i used zeovit system and than used vodka again for a long period of time. my P04 and N03 were undetectable after used of vodka as compare with zeovit system. and the colour of my sps was awasome (you can check my old tank thread).
my corals were healthy and all my sps grow real fast. i have to frag it almost once in 2 weeks. just one fine day (as usual, nothing change... no additional of things, all parameters within it specs), within a week, 1/3 of my sps experienced burned on it tips and it turned darken after that it started to RTN from the tips. in fact, it can still hold in this condition for a month with this condition till it totally die. no matter how much water change done... all parameters within it spec and still, one by one all my sps experience burn on it tips, darken and then RTN from there. so, decided to sell the rest of my sps to save them.
after that, all my lps also suffer the same fate. all my acans gone within a month.
i cleared up all my sps and lps and just keep fish with LR for a period of one year. just hope that i can reset the whole system. after a year of break, i tried out sps again. and i can never have it survive in my tank for a week. same issue, it started to get burn on it tips and then RTN from there onward. at first i thought may be my mag gave some problem or off spec. checked all my parameters, everything is within it spec. my cal reactor till running strong even without any corals for a year.
i thought may be my system needs sometime. stop dosing anything. just gave it a break. just keep my system run for another 6 months and try again. i started collect of zoa after that. at the same time, i tried out monti. however, i can never be able to hold it for more than 2 weeks this time. it got burn on it tips and then RTN from there onward.
i only used zeovit system for a short period of time. dosing of vodka was the longer.
this experience is just base on my personal experience and encounter. may not true to anybody.
joe_p, you started sps longer then i am. i am sure you have much experience in it.