Need Help - on lites MH how much is TOO much

[bj]

Went to a manufactuer's site we won't mention any names... I have 110 High 30" tall X 18" wide X 48". Brand new tank setup. Will eventually be reef - very few fish. Was all set to buy retro kits (very good price) and go with 250W and the 12000K bulbs. (2) kits and the 16" reflectors under them. Emailed the company to make sure my canopy which is 6" high would allow the installation without "nuking" my glass top. I figured to instal fans on opposite ends to cut the heat. The company comes back and recommends going 400W because of the depth of my tank. Good advice or trying to make a bigger sale ? According to the "secret formulas" I need 450 ish Watts total ? Does the depth add the need for that much more ?
Thanks for all the help - this a great resource.

 

[biggdriver]

I would recommend going with the 400..Italso is going to depend on what kind of corals your will have...You can also suplliment the MH with some actinics to tone down the intesity for your eyes

 

[mlm]

In that deep of a tank they were not trying to make more money you really need some good light penetration to get to the bottom.