2x400w or 2x250 MH for a 90G?

[knightmetro]

I need an honest NO BS answer to this one guys.

I have a 90G reef tank I am putting together. My canopy is 14" high. I'll be mounting a metal halide retrofit system to the top of the canopy. So, it should be 10-12" off the top of the water.

What is BEST for this size tank?

2x250w or 2x400w?

I DO NOT WANT TO HAVE TO PURCHASE A CHILLER. PERIOD.
I have no problem mounting some clip on sooling fans to the back.
I will be installing a retrofit kit for t-5 tubes as well for more actinic.

I just want to know weather or not 400 or worth the extra, or just overkill.

Thanks guys.

 

[victor626nj]

go with the 250hqi and drop them lower mine are 2 inches from surface of water and no heat issue also my tank is right under my ac vent and fan blows in cold air

 

[glxtrix]

if you get the right stuff, you can get 250W bulbs to put out as much PAR as 400's. Thats what youre looking for here, PAR! Just because its a 400W'er doesnt mean its going to perform better. Do your research on bulbs and ballasts and pick what you think will work for you. Also what type of tank you going to run.....softies, lps, sps?? that a huge factor there too. softies and lps dont require all that much light. If youre going to do purely sps 400 might be good, but like I said you could get away with 250's. Look for efficient ballasts, high PAR bulbs and you'll get the best of both worlds....low wattage, high PAR, cooler temps all that equals less money. Money not an issue, hell go with the 400's and that way you'll have more light for when you upgrade Its going to be hard asking whats the best setup....people have different tastes for lighting. Do your research and think whats going to be best for you. IMA also, dropping lights 2" above water surface might not be the best for light spread...yeah youre gonna get more PAR....but youre reducing the surface area of that light beam, esp with an HQI.