quite honestley i don't care what it leaches, as long as my corals are happy!! which seems to be the case. i have used the zeovit system when it first appeared on the market, with mixed results i must admit. then there was very little info the,whole lot seemed strange at the least, info was a one sheet papper with large print! i stopped using it then after a few months because i could not see a difference. also it was quite expensive shipping it in myself!
but times have changed, zeovit systems have grown (i do not say improved that's up to everyone who wants to use it).
i have seen lots of tanks that use it at the moment and i must say i liked the looks! so i probed into it abit more and found that the whole system has changed a lot since then, there is a zeofood7 out now, i used just the food with no number which means that a lot has changed and most likley will keep on changing in the future.
corals die, most of newly settled small acro's will perish in nature. i have seen it in tonga (200 dives in one year), in the maldives (70 dives in 6 months) and recently in the cooks. lots of small acros just die because they settled in an unfavoured position. most of our corals are just that, small pieces of different acros and yes lots will perish or struggle to survive in our aquariums. i have seen perfect puple/blue/ pink specimens only to see them bleached a few days/weeks later. and this happened regarding temparature!
so to blame coral loses on a systems is narrow minded, what ever system you use you will have loses, some of us are pretty good to keep them at a minimum, but i would like to know the person who hasn't lost a single piece???
iron or not iron, rowa or MM it doesn't really matter that you use as long as your corals look healthy and grow. and if a systems is able to grow corals faster then others (maybe its just survival of the species that makes it grow faster which could well be the case with shallow acros as competition is fierce) then we should be grateful and shar those acros around, i would rather give lots away the have a tank with very slow growing and dull liking stonies in my tank!