Optimal Orientation of MH Bulbs?

[StirCrazy]

In a 48" tank with two bulbs you should mount then front to back to get the maximum light distrubution. also you should shift the base of the bulbs as far back as you can as more light is thrown forward from the bulb than back wards.

a different case would be in a tank like mine where it is only 3 feet long and two foot wide I have them mounted like you do in that case as there is only 1 foot between the tips of the bulbs.

Steve

[danny zubot]

Ok my turn. I have a 36x18" tank with only 1x 400 watt MH ver it. My current relector is only a bit larger than 1 foot squared, and my bulb is perpendicular (front to back).

The reflector I'm changing to when my canopy comes is 36" long so the bulb must face parallel. How far off of center should my bulb be to cast optimal light on the center of the tank? Also, the new reflector doesn't have one of those "V" shaped light deflectors that go above the bulb. How much do those actually effect my lighting?

[StirCrazy]

Originally Posted by danny zubot

Ok my turn. I have a 36x18" tank with only 1x 400 watt MH ver it. My current relector is only a bit larger than 1 foot squared, and my bulb is perpendicular (front to back).

The reflector I'm changing to when my canopy comes is 36" long so the bulb must face parallel. How far off of center should my bulb be to cast optimal light on the center of the tank? Also, the new reflector doesn't have one of those "V" shaped light deflectors that go above the bulb. How much do those actually effect my lighting?

your not going to be able to cast optimal lighting with one bulb on a 36" tank. If you go by the rule of thumb 2X2 foot for each SE bulb, you will see that like my Garage tank, no matter how you place the bulb on the tank you are going to have areas that have much lower light intensity.

the way I would do it if I were you is on an empty tank or maybe the kitchen floor flash your light up with white paper under it and see how the lighting patteren is.. then you can shift it around to the point you are happy with it.

Steve

[GMGQ]

FYI, despite the interesting swing in the voting, I decided to change the bulbs to front/back aka Perpendicular to the front of the tank. And I lowered them 6 inches:



The tank is definitely brighter, and I think the lighting is more even now. We'll see how my corals like it.

[TheReefGeek]

Your pfo optimal perpendicular reflectors are meant to be mounted perpendicular, so that is how they should go, I assumed you would have changed them after learning that.

[GMGQ]

Yes, that's why I changed it despite the swing in votes.

But I have seen a lot of people mount them Parallel too. Heck that's why I originally had them parallel.

Originally Posted by TheReefGeek

Your pfo optimal perpendicular reflectors are meant to be mounted perpendicular, so that is how they should go, I assumed you would have changed them after learning that.

[TheReefGeek]

Definately. I would have done the same if I bought your reflectors, because I currently use their 36" reflectors, which obviously go parallel, so I would have done the same.

So I guess everyone should double check with the manufacturer of their spider-type reflectors to make sure they are using them in the correct orientation.