400 watt halide over 85

[OceanMist]

would putting a 400 watt Halide over an 85 gallon be a good Idea?

I have found a good deal; ballast, reflector & lamp for only £100, as the light is meant for growing things, I would obviously have to replace the lamp (around £70), but £170 seems good for a 400 watt aquarium Halide, and would be cheaper than buying 2x 250's.

The problem would be that the actual lamp would have to be 4-5" from the water surface, so heat would be a problem, but I could thow in a few fans which would help,

would I be able to keep anything I want under 400w, 18" high tank?

 

[xkenneth]

You're talking one 400Watt bulb. Unless it's a square tnak, you won't get much coverage.

 

[ccCapt]

You get about a 2'x2' square coverage area from 1 MH. If that's a 4' tank and has a center brace, 1 bulb won't work very well, plus the center brace will cast a shadow.
Also, 4"-5" probably isn't high enough above the water. I think a 400w bulb that close will cause some serious heat issues.

 

[OceanMist]

You're talking one 400Watt bulb. Unless it's a square tnak, you won't get much coverage

The tank actually is a square , ... or close enough, 3ft x 2.5ft, so it would cover nearly all the width, and only leave 6 inches either side of the tank, the halide would also be used with 4x 55 watt compact fluorescents and a 30 watt moonlight fluorescent ... would this be overkill ??

How could I prevent heat issues from occouring ??

 

[Hara]

Why do you feel it has to be so close to the water? You will notice a temperature difference with every inch above that you go. Recommendations on my MH lighting was 12 inches above the water. Fans mounted behind, on the wall will help tremendously. With it raised a little higher, you will also have more coverage.

 

[OceanMist]

Yeah, I know, only I would like to avoid 'adjusting' (using a saw) my hood, If this is at all possible, also because the light i'm looking at is not a purpose built aquarium halide, it would look ugly plus it would blind you everytime you look in that direction because of the 'open' reflector.

 

[Hara]

Wow, I didnt realize you were going to put it in a hood. I would just about bet that there is NO way you will keep the temp manageable without a good chiller. I would be looking for other options.

 

[OceanMist]

Yeah, I do see the problem it would cause, I may be able to alter the hood somehow.

do you not think if I fitted about 10 computer fans in there with vents I could control the temp?

 

[Hara]

I have my lights way off the water, 2 big fans aimed at the space under them and towards the water. Most of the time no enclosure. and alot more surface area and my water stays around 83.