Let me start by saying I've read the 5 page (plus additional hyperlink info) on lighting in the "Monster Island" section and other searches online...
I've got a 40gal reef setup that I run 4 PC
's on. When my wife let me buy this 90gal rig for my birthday I nearly did cartwheels down the street (except for the fact I'm not that coordinated to do a cartwheel.
So on to the meat and potatoes part...
This 90gal is a 48"x18"x24". It has a trapezoid overflow 1/3 in on back left. I custom built an oak stand (with my neighbors help, he designs/builds fun centers for a living). The 12" high open-back canopy was built with the intent of doing a MH
mix with PC
in a retro rig. I started researching about the new T5 lighting and thought... maybe that's the way to go. Now I'm all confused. The concern with MH
is HEAT! Not $$ well maybe money if I have to buy a chiller to keep my water temp low enough (consistently 77-80deg). I want to be able to keep clams eventually. I've got a buddy that keeps a clam with 96Watt 10000K PC
in a 135gal, though I've been told that's not recommended. I don't want to kill something that has taken YEARS to grow to the size of my hand because I don't have enough light. Rambling again... sorry.
So I can install a 6 bulb T5 retro or... I could do a 2 bulb 250W MH
with 2 40W VHO
Seriously though, how much will the MH
heat the water if it's 12" off the top of the aquarium with several fans moving air out from under the canopy? How much usable light do I loose by mounting the T5 lighting in a 12" canopy?