This following statement is purely from my experiences....this is in NO WAY fact....there.....there's my disclaimer
I see tank after tank with tons of equipment (Skimmers, Reactors, RO\DI) and dosing all going on.....and crash....then I see these tanks that are like mine....in the eye's of the fellow reefer they are "neglected" or simply not taken care of well because we use tap and you know what....I don't know anyone personally that uses tap and had a crash.
Seems the more dosing you do....the better chance of crashing....the more equipment or reactors or what have you....the better chance of crashing
again....this is not a fact....just my opinion. Do I recommend others to follow my lead.....no....why because I believe your tank actually only rely's on one thing... consistency. If you are a doser....then you need to consistently keep dosing to keep your levels the same....if you use reactors then you consistently need to clean em and change out the media's to keep everything the same....if you are like me (water changes every 3 to 6 months and using tap) then stay consistent.
Seems when I am consistent....I get consistent growth and happy corals and fish. When I deviate and do a bunch of crud to my tank I have issues. So....back to the regularly scheduled program I go. I have a buddy with a 240, 2x180's, and a 60....he has every reactor you can think of....a few hundred dollar RO\DI set up....doses like mad....and he currently is rebuilding his stock after all but the 60 crashing. BTW....the 60 is his daughters tank....she does very little to it.
Final disclaimer.....this is just my experience and opinion.