[mjasgt]

I am trying to build a dual 175 MH lighting system. From reading the various boards, I think the equipment needs are

Ballasts - how many? 1 for each light or will one cover both lamps?

mogul base - is each wattage a different size or is a mogul base generic?

parabolic reflector - one for each lamp or one for the whole set-up?

fans - are two 3 inch fans sufficient?

Power cord - supplied with ballast?

Any help would be appreciated.

[dattack]

Sounds good.

They have a DIY kit at http://www.hellolights.com/25methalretk.html

Might be about the same price if you get all parts locally from your lighting store. Not sure what ballast they use however.

[kevinpo]

Here is a good place for DIY lighting.

http://www.marinedepot.com/a_lt_mh_pfo.asp?CartId=

I would get the 36" PFO reflector (it will give you better coverage) and the dual ballast (comes with power cord). This reflector also holds 2 95W VHO's or PC bulbs (mounting holes are already drilled). Get the mogul socket with lamp cord kit. It has a quick disconnect from the ballast.
Mogul sockets are the same size for the different wattages so you can upgrade later without having to buy new sockets and cables.
Two 3" fans will be fine if you keep the ambient temp. around 72-75F

HTH,
Kevin