lighting rules?????

[itnerd]

I want to test the rules a bit.
I see that the spider reflectors claim 36" coverage when mounted perpendicular to the front glass. Why run 3 250W MH w/ VHO if I could run 2 400W MH and 2 160W VHO's.
I have read the rule on 1mh per 2'x2' and have seen 225G lps tanks look great under 2 250W w/ VHO .(72"x24"x30")
For example: 2 400W MH with 2 160W VHO over 180G = 6.22W per gallon. As I understand things...very adequate for most any coral with the exception of the most demanding SPS.
Another example: Same configuration as above over a 225G
would create 4.98W per gallon. This is on the low side but still adequate for LPS and softies.
My reasoning is to eliminate a bulb/ballast/reflector/outlet and save space = (air movement) under the hood.
If I mount the bulbs 12-15" above the surface and the VHO's very close, is this workable?
Thanks

[ridetheducati]

The lighting rule is not a rule, just general guidance.

I have a 6 foot SPS dominated (center brace) reef with (4) 400w MH. Two MH sharing one spider reflector.

Canopy suspended 11 inches above water line. No noticeable shaded areas.

(2) 400w 6.5k
(2) 400w 20K Radiums HQI

You should be happy with (2) MH over a 72" reef. Unless your tank has 2 braces. That will be tricky with 2 MH's.

[itnerd]

I really like the idea of using less hardware. Thanks for the response.

[rwag]

itnerd,
I have three spiderlight reflectors covering
my 72" tank all with 250w iwasaki bulbs.
I feel the lighting would not be dispersed with only two reflectors. Maybe they would be ok with 400 watt bulbs suspended very high but I wouldnt think so.hth
Ryan

[itnerd]

I have decided to run 3 175W MH and 2 160W VHO Actinic over a 180G. This would be 4.69 watts per gallon. From what I've read, this is adequate for LPS and softies. Would you all agree?

[rwag]

I think you would regret not getting the 250's
I have 2 175 on my 72 gal and I went with three 250's on my 125 and I am so glad I did. It looks so much better.
Ryan