3 x 175 MH or ?

[Sebastian]

I have three Spiderlight reflectors over my 75 gallon soon to be
reef tank and I can't decided on just how much light. I have to
keep it realistic so I won't need a chiller (no room in stand and
no basement). I plan to keep SPS, LPS and some softies. The
canopy also has four 35 cfm fans for heat dispersion.
My thoughts on lighting are :

A : 3 X 175 ( one 10K and two 12k )
B : 2 x 175 and 1 x 250 ( two 12k and one 65k Iwasaki )
C : 2 x 250 and 1 x 175 ( two 65k and one 12K )

I have two 175 12k Sunburst bulbs already, other than that
the combinations are limitless. Any opinions ballasts and
bulb combinations will help.

[RobG]

How long is your tank? 48"? From what I've been told & read (And done myself), you only need 1 MH for every two feet when using the Spiderlight reflectors bringing you to two total MHs, not three...

[Sebastian]

The tank is 48" long and made from 1/2" glass so no center brace
was needed that is why I chose to use three instead of two.
Also there are two 46" vho atinics on the tank.

[Ironreef]

I would go with 2 _250w if you feel a third is needed add one later. If you want dedicaded sps i would just get 2 400w. Probally the same as 3 as far as heat and watts except with 3 you can shut one down sooner if heat is an issue. If you plan on keeping it a mixed reef 250w will be fine.

[organicreefer]

sebastian,im setting up a 48" tank and i plan 3 halides with spiderlights .theres nothing wrong with three,though it isnt neccessary.im using two 175w 10k's with a 400w iwasaki in the middle.i happen to have all three ballasts so i decided to use them all and have them come on and go off at different times to create a more realistic light cycle,as well as have "the best of both worlds".i get to have a 400watter,but i dont have to deal with the heat issues of having it run for 10-12 hours(it will be on for just 4). electricity savings is also a plus two four hundreds is fifty more watts(though im not sure if i calculate three ballasts intsead of just two,hmmmm?).but ,in the back of my mind somewhere i know they are really just toys

[golfish]

Yeah, I would go with 2x250 watt Iwasaki's and the 12K just to add a little blue, that's about all their good for. From what I have read and seen the 250 watt Iwasaki runs best on the PFO standard ballast...

Mark