800 watts metal halide lighting too much for 90 gallon?

Also the reflectors will make a big difference.
What are the dimensions on the tank?
Good read on reflectors:
Advanced Aquarist's Online Magazine - Product Review: Analyzing Reflectors: Lumenbrite III, Lumenmax Elite, Lumenmax, and Lumenarc III

 

This is the link to the setup. Can't find any info on the ballast.

Hamilton HQI Reefstar Lighting System

48" L, 24" H (22 w/sand bed), and 18.5" W

the reflector is a hammertone reflector

 

You mean 18" dep and 24" tall, right??

if it is a std size 90g, that is what it is.

I had a 90g with 2x250w of xm10,000k halides on it. It grew stuff well, despite the horrible reflector I had for the halides.

Don't go with 400w halides, it's not necessary.

 

Looks like a decent reflector but if you go 400W I would go with single ended bulbs. Not many choices of bulbs in the DE 400W category.

I would go 250W if I were you.

 

At the tank here at penn state we have 4 400watt iwasakis and the sps growth is INSANE!!! But it's also a 500 gallon tank. I would agree with everyone else on the 250's

 

I think 2 400's over your tank is ridiculous. go with 250's. which will be absolutely perfect.

think about heat, heat, heat, heat, and more heat on top of neeeding a chiller. and on top of those factors think of your electricity bill. all that heat will make your chiller work harder and boost energy consumption.

I can keep absolutely anything in my tank with 250's and have no problems with lighting...

 

bought the 250's....got a killer deal on them. Just need to find some hanging wires.

Thanks to everyone for the great responses

 

i say go four it, you can shorten you lighting cycle if its too much

 

I have two 250 watts 15k lights on my 55 gallon, at first i was worried because a lot of people told me I would cook the corals in my tank, but I have had the lights over my tank for a year plus now and everything seems to be fine. I just had to reduce the time the lights were turned on every day to 7 hours. Its a little short for the lighting period but it works. i would say go for the 250's.