Cool Topic!!!
I have to say that there are two hardware items in my 92-gallon reef system that really made a difference when purchased and installed (
and still working just as good as they did the first day they operated).
There are my AquaC Ev-180 skimmer and my NatuReef Denitrator.
Everyone always says "that a good skimmer makes a big difference"...That is absolutely correct!!!! You really notice and appreciate the difference when you upgrade from a regular, everyday type skimmer to a good one. When I saw how much of a difference this skimmer made in my big tank, I went out and purchased the AquaC Remora for my 20-gallon reef. Yep...That made a hude difference too!!!
The Denitrator from NatuReef was not a cheap purchase either, but it has all but totally eliminated the Nitrates in my tank!!! I can feed all I want and have almost no Nitrate issues. The only time I really start to show a very limited amount of Nitrates in my tank, is usually just before the monthly water change.
I just recently purchased a 250 w double-ended MH. But since I have not installed it yet, I can't report on this yet...Hopefully soon after the new year.
Good Luck and Have Fun!!!;