Light Setup - MH & VHO in DIY Canopy

[npaden]

I have a 72" x 16" (120 gallon) top dimension that I am in the process of building a canopy for. Current plans are a 14" tall canopy to keep MH 10" above the water. 1) - Is this high enough? 2) - Do I need to put the VHO tubes up that high to avoid shadows or can I leave them close to the water for maximum brightness? I have 2 175W 10K MH that I am adding and plan on having them close to the middle about 18" apart facing toward the ends of the tank. How does that sound?
Now after reading on the reflectors in badgers post, what type of reflective material should I use? I guess the best would be polished aluminum for the VHO's and White Glossy paint for the MH? That would mean the VHO's would definetly need to be as high as the MH. I thought this was looking to good and now bummed on the refectors! :) Where can I buy polished metal reflectors. I was planning a 45 degree angle in the canopy to reflect the light down, maybe I should use 3 - 30 degree angles all painted white? and polished aluminum above the MH & VHO for complete reflection and heat safety for the MH. Thanks in Advance for any advice or suggestions. Nathan

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[Joez]

Lots of recent info on the board concerning reflectors. I think there is a range of acceptable, if not perfect alternatives.

As for the distance above the water, 10" minimum is not required. My MH and flourescents are between 6-8 inches and don't suffer from spray or splash.

IMO trying to set the different types at different heights is more of a challenge than the benefit warrants.

[This message has been edited by Joez (edited 12-01-1999).]

[Playfair]

Npaden,

I really love the way my canopy turned out, which was partially by accident since those darn mh bulbs were bigger than they looked...

Joez is right- keeping the mh only 6-8" from the bottom of the bulb to the water is sufficient.

The placement of the VHO was the hardest part; I ended up putting them significantly lower than the mh which helps diffuse any shadows.

I used the $20 reflectors from ALS, which seem to work well. Just draw the profile of the canopy on paper, complete with reflection lines from the bulbs.

See my construction page for some more info, linked from my reef site...

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My reef:
http://www.fortunecity.com/petparade/fins/1/reef.html

[This message has been edited by Playfair (edited 12-02-1999).]

[npaden]

Playfair, one problem that I have is the width of my tank (only 16") this doesn't leave very much space for the MH to shine through between the VHO's. I definetly like the hinged from doors for access and not having to worry about the lights when I openned and closed it. Several have told me to mount the lights perpendicular to the tank and the narrow width is a problem there as well. Also, who is ALS to buy the $20 reflector from? Is that that long one you put above your MH? Also, how would I go about drawing the relection lines? My limited thoughts on this would be that the reflector should be smaller than the overall canopy to accomplish the best results as far as reflection lines go. This would allow it to spread out over the tank as opposed to spread out onto the floor outside the tank. This gets me back to the problem on the limited width of the tank. I have thought about having a seperate polished aluminum reflector for each 6' VHO tube and a 1 or 2 white reflectors for the MH depending on mounting parrallel (1) or perpendicular (2). Would the fact that I would have to mount the VHO tubes higher outweigh any benefits of the reflectors? Also if I had reflectors on the VHO tubes and they were lower than the MH that would cause a shadow unless the MH was directed very closely between the VHO tubes. Thanks for any input on this! Nathan

[ignatz]

Nathan,

Sorry, I'm a little late on the reply. I hope what follows helps some.

First, I bought polished aluminum from Aquatic Technologies (http://www.aquatictech.com/). They will cut and bend it to whatever shape you like. Second, I think that if you are only going to use two MH, then I would consider using SpiderReflectors. (You can get informaiton from Digital Oceans (http://www.digitaloceans.com/). Third, if I'm not mistaken, you can buy fluorescent bulbs with built in reflectors. If I were in your postion, I would consider using this type of bulb. You can then easily mount them at a different height than the halides. For example, if you were to build a small ring around the tank out of 1X2's then you would have the perfect ledge to sit the fluorescents on. You could mount the halides at the top of the hood, and you would be set. Again, I hope this helps, and if you are interested I have some good plans for a hood this size.

HTH
~ignatz

[Playfair]

Sorry, I'm a LOT late on the reply!

Ignatz has some good ideas, you just have to modify to make everyones input fit.

ALS website: http://aquaticlight.com/

You would need (3) 2' reflectors (I have 2).
Here's a hint: No guarantees, but I talked the guy into giving me the longer 2' reflectors ($32) at the price of the shorter 16"($25 ea). They work pretty well. I had to bend, twist, and cut to get them to fit my exact area, and they're only about 1' wide. There's no reason why you can't fit the flour. tubes under the same reflector...

[npaden]

Ignatz, thanks for the input. The problem with the spider reflectors is my width being only 16". The spider reflector is 13" wide and 16" long so if I put it in perpendicular there wouldn't be room for anything else and parrallel there would be only 1 1/2" on each side. I guess that would be room to stick a flourescent tube. The hood plans currently are for the front to open with hinged doors, not decided whether top or bottom yet, and an open back design. The spider reflectors are a little pricey as well (more than I paid for my used MH setup w/ 6mo. old bulb), and I already have a socket and everything. Oh well, any additional input would be appreciated. Thanks, Nathan

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