Halide installation question

[brewercm]

Has anyone checked to see if they get a better distribution of light by running the bulbs parallel or perpindicular to the tank. I'm using standard spider reflectors with two 400 watts on a 6 foot tank. I want one in the middle but with the bracing I doubt it would get much light through, maybe anything is better than none if needed and I'll add it.

[dow]

I read an article when I was initially setting my tank up (sorry, can't remember which article) that recommend running the MH bulbs perpendicular to the tank. I currently have a single 10K 175W pendant over mine (home made) and it gives a very good coverage. Tank is a 45 breeder (36L x 18W x 16D).

HTH

[Bucky-Katt]

You know, i was thinking about the same thing. I am in the planning stages of upgrading my tank. I am looking at moving my livestock out of my 90-gallon into a new 180 or 215 gallon Oceanic Reef Ready set up. Lighting has been a nagging question. Unless they have changed, I have a 125 gallon Oceanic tank that has a glass center brace on it. if the 180/215 set ups have it, is it a good idea to put a third light over the brace? Will it do any good?

Hope you don't mind me jumping in here with this question.

thanks.

BK

[matt]

Sanjay Joshi did an extensive study on exactly this. He compared the light spread and intensity of several reflectors, and the results are very helpful, although you may end up wishing you bought the PFO reflectors instead of the spiderlight when you see the study. It's in reefkeeping or advanced aquarist on line mag; I can't remember which one he writes for. About a year and a half or so ago, just check out the index for those mags and you'll find it.

Basically, if you want a more rectangular spread, use the parallel reflectors, if you want a more square spread, the perpendicular ones. If you're using 2 bulbs over a 6 ft tank, I assume 24" front to back, then you need the spread for each bulb to cover a 36" by 24" space, right? That's probably best done with the PFO parallel reflectors. But using yours, only turning the bulbs parallel, might help with the spread as well. Check out that study, you'll find the info you want.

[::pete::]

I run mine parallel it makes the light spread like Matt said, in a rectangular pattern covering more space. As most tanks are 24"-30" deep you really wouldnt need the light spreading as much from front to back as you would side to side (the longer dimension). Also if you choose to use different bulbs (10K/20K) in a mix, if they are perpendicular to the front of the tank giving the square spread there is a better chance for you to see the difference when viewing the tank.

[brewercm]

Yeah, I remember reading that till my eyes were bleeding one day. I remember the spread and intensity was also much better with DE bulbs but since they don't make those in 400 watts I'll just dream. I'm probably going to stay parallel the way I had them on my 75 and see how things work out. If need be I can always change over to PFO style reflectors later if that will help out more.
I actually had two of those about a year ago and sold them. :x