How do I use Metal Halides in a short hood (~5")?

[Grouper]

Last night I measured the distance between the inside roof of my hood and the water surface and was surprised to find it was a mere 5".

I want to mount MHs but I'm concerned that I may not have enough room between the water surface and the bulbs to avoid splashing, unless I use a pendant and mount it on the hood (buying a taller hood is out of the question because it would be difficult to match the color of the base).

The PFO mini-pendant 250 HQI is 4" deep, giving me a mere 1" between the water surface and the glass of the pendent. The bulb is, of course, encased in the pendant and I estimate would be about 3" away from the water.

Finally, I am also concerned about the heat the bulb would create so close to the water surface, although if I use the pendent idea the heat would at least have to pass through the glass.

To make matters worse, there is not enough room to place 4" fans on either side of the hood because of a cross support bar in the hood. The only option seems to be to drill a hole on top of the hood and place two fans there.

How do I solve this problem? Thanks.

[Salt-Reefer]

I would love to hear a response on this subject as I'm in the same situation minus the fans, I did have the room for a 4" fan in each side which does keep my PC's cold. I want to also put the 250 watt Iwaski's on mine. So here it goes...

UP^^^^^^

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Salt-Reefer

[This message has been edited by Salt-Reefer (edited 01-18-2001).]

[Ninong]

Grouper ~

IceCap puts out a mini hood that is only 11.5"L x 7.5"W x 3"H.



You can get it with the 250w 6500K Iwasaki bulb or the 250w 10,000K HQI double-ended bulb, at either www.marinedepot.com or www.acropora.com

Ninong [img]/ubb/smile.gif[/img]

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Irrational Exuberance!

[Salt-Reefer]

Grouper, I hope its ok to piggyback on your thread but it kinda relates to my application also.

Ninong or anyone,

Would there be a problem with using the IC retro-fit type application with this kind of height ~5" of clearance between light and water? Whould the light from the halide cover a big enough area? It would have a reflector going alomost the whole width and lengh of the tank 60"x18". Lights would mounted long ways to the lengh of the tank. 2X250 MH

Thanks for (hopfully [img]/ubb/smile.gif[/img] ) letting me add in.



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Salt-Reefer

[Ninong]

Salt-Reefer ~

I guess you're talking about mounting your lights parallel to the front of the tank; in which case there are reflectors that are specifically designed to be mounted parallel rather than perpendicular. Spider-lite reflectors, for example, are designed to be mounted perpendicular to the front of the tank.

I'm not sure if you are talking about 5" from the actual bulb to the water, or a total of 5" clearance in the canopy as I believe Grouper is talking about. Anyway, 5" from the bulb to the water is certainly workable. It may not be ideal but it can be done. It is always difficult to try to get metal halides into one of the standard size canopies that come with most tanks.

If you are mounting your 2x250w bulbs in a long parallel reflector that runs the length of the tank, it should be fine, especially since your tank is only 18" wide.

Ninong [img]/ubb/smile.gif[/img]

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Irrational Exuberance!

[BigA]

Why not cut a hole in the top of the hood and put the MH bulbs/fans on the top of the hood? I think I'm going to try that this summer when I add 2-250 watt bulbs to my 75gal. Should be able to push a lot more air past the MH bulbs that way too.

~BigA

[Grouper]

Thanks to all who responded.

I am probably going with Ninong's suggestion of the mini-hood. Ninong, I have not heard much with regards to the PFO Mini-HQI Pendants and Bulbs, have you? Are they worth the extra money over the 6500k Iwasakis? I have the money to spend on them, but I wonder if it is worth it.

BigA's suggestion is intriguing, but unfortunately my wife would never go for it. The tank is prominently place in the middle of the living room and you know how that goes...

JA

[Ninong]

Grouper ~

I am wrestling with the same decision myself. I would prefer to have 2x400w 6500K Iwasaki's plus 4x95w URI VHO Super Actinics (110w won't fit), but I don't believe I can manage the heat issues for more than one reason.

Therefore, I am leaning in the direction of 250w 10,000K HQI double-ended lamps because they have more PPFD than any of the 400w 10,000K MH mogul based lamps. They also have the advantage of running cooler than 400w Iwasaki's and having a more attractive (to me) color, that would not require half a dozen VHO actinics to make me happy. (Also, right now www.petwhse.com just reduced the price of the lamps from $129 ea to $85 ea.) And, of course, it goes without saying that a 250w lamp uses less electricity than a 400w lamp.

Ninong [img]/ubb/smile.gif[/img]

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Irrational Exuberance!

[BigA]

Grouper,

With a few fancy cuts and some trim, my hood should look like it was made that way. OTOH, you can make a nice DIY oak hood for about $60...That way you can make it fit the tank, lights, etc.

~BigA