How much light for a 75 gal reef?

[npage]

Getting a 75 gal tank, 48" long x 18" wide x 20" deep.
Can't go with MH because WAF demanded a canopy. (WAF=Wife Acceptance Factor

)
So because of the heat issues Going with T5 Retros.
I would like to eventually keep soft corals, mushrooms, LPSs, BTAs, and maybe a clam. I want a nice bright tank, but I don't want to go too far that the fish need shades.
Can anyone tell me how many bulbs / watts I need to do this?
I've been through the archives and couldn't find an answer that fit my requirements without bringing up MH.
Thanks in advance
Nick

 

[reefiness]

i would go with 6 of the 54 watt bulbs

 

[mandarin w]

I have a 8x 54watt, set up, it is 48inches on my 75gal, It is a sweet setup. You will like these lights. But the only down side is you don't get the shimmer you get from MH. You could put MH in a canopy. Just use fans to pull the heat out. Alot of hobbist do with not much issue. I used two fans on each end of the canopy blowing cool air in, and at the top of the canopy I had two fans blowing out. This worked out very well for me. I just went to lowes and got the wood grain heat vent covers. Cut out the 4x10 section of the canopy on each side. Went to Radio Shack picked up 6 computer fans. the ones that run on house curent. Mounted two fans on the inside of the canopy on each side behind the wood grain vent. No one even notices the fans are there. It just looks like some fancy detail for the canopy. ON the top (since it too high for most to see. I just used reg vents and put the fans inside blowing out the top. My temp with 2x250MH and 2x96 actinics never went over 79.4. Definatly not hot enough to need a chiller.
Both ways have thier pros and con's.
If you got the T-5 route, try to get the individual reflectors on each bulb. It will put more of the light in your tank. But with the T-5's you should be able to keep pretty much anything you would like.

 

[gtiguy]

Ive run PC's for 2yrs (on my old 30g and half way through my new 65g) and for the most part the tank worked out great with the exception i only had mushrooms/leathers/and some LPS...I even bought a 2-39w T5 fixture recently and added it to the mix but what i began to notice was the colors on my tank were never that great (actually the tank starting looking more yellow which was very frustrating) ....Besides if you want to do some of the things you are interested in going with T5s, you would need at least 6-8 bulbs in the fixture and even than you might not be that happy with the coloring aspect...i actually took mine out at this point and put 2 acntics PC's in for my day/dusk effect.....and now have 360 total watts...but read on....
Point is my room has always been hot, it used to be an attic...so heat was always my enemy, but luckily i have a great ac but yes the electric bill, but usually only in the summer is that hot so its never been that bad....So to make a long story short lol i got my hands on a hand me down (actually brand new) Single Pendant HQI Metal Halide 250w 20k :scared: ...Mounted in my fairly new canopy and walaaaaa...WowW...I cant even begin to explain the tank difference, the color difference on corals that i thought were one color but were actual another etc...as for the heat....with a small fan pointed on the canopy for now (summer) the temp doesnt go beyound 79-80....

 

[npage]

Thanks everyone. That's just what I was looking for.
I should be getting my stand and canopy this weekend. Once I get my hands on the canopy I should have a better idea of what I could fit in there. Mandarin w, great idea on the vent cover, I hadn't thought of that. If there's enough room for large enough fans I may go with a MH T5 combo. (I cant stand the whine of small computer fans)
Does anyone have any recommended brands of fixtures?
Nick

 

[mandarin w]

I had 6 of the 4 inch fans in my canopy. I never really noticed it. But with the filter and skimmer going I guess it all sort of drown each other out. As with all things, after about a week or two you become so used to the noise, you don't even notice it anymore. But really I don't think any of it is that loud.