How high should a 400w MH be?

[CHEAPREEF]

Hi guys, just wanted some opinions on how high off the water surface a 400watt Iwasaki should be. I'm finishing off my new hood on tuesday and need a rough idea where my mounting brackets should be. The hood will contain 1 400 watt plus 2 overdriven NO actinics to 80 watts each. It will be a free standing hood with open areas all round. It's going over my 75gal with a 15" water depth (afetr 4" DSB). I was thinking 8" From water surface to bottom of MH, what do you guys think?

Thanks
Clinton

[Dez]

Hey Clinton, I think it's really up to you. I chose 6 inches for mine because that's what I read in books and stuff...to have metal halide lighting at least 6 inches from the water surface. But then there's Eli who runs it only an inch above the water... I thought it was crazy and risky but he's been doing that forever. 15" of depth is not much at all...you'll get a nice punch with your bulb. Does it look asthetically pleasing with it 8 inches above? If it does...go for it. I still want to come by and see your tank sometime.. Call me..

des

[One_Divided]

I'm making the hood for my 50g 10".. the 400w iwasaki will be on an adjustable track so I can raise or lower it to find the right spot.. also this will give the option to raise the bulb if acclimating to new light..

just an idea.. lots of versatility is always the best way to go..

-Adam

[CHEAPREEF]

Yeah i'm really not that worried about "asthetically pleasing" I would like it to work the best for my clam and corals. The canopy will be adjustable up from the 8" to 10" and 12". I just wanted to know if the 8" off to start is to close or to far? Thanks for the replys. smile.gif

Clinton

[FishGeek]

beacuse you are running only one light in the middle, you have to worry about the pread of the light. If you mount it too close, the light wont cover very much of your tank. I say mount it highter so the light spread covers more of your tank. Don't forget that you have a shallow tank and 400w metal halides are good for tanks 36" deep so i don't think you have to worry about how close to the tank surface you mount that sucker!!!! Just my opinion.

Oh yah, did you get a clam already?

Simon

[seahawkjohnny]

Originally posted by CHEAPREEF:
Hi guys, just wanted some opinions on how high off the water surface a 400watt Iwasaki should be. I'm finishing off my new hood on tuesday and need a rough idea where my mounting brackets should be. The hood will contain 1 400 watt plus 2 overdriven NO actinics to 80 watts each. It will be a free standing hood with open areas all round. It's going over my 75gal with a 15" water depth (afetr 4" DSB). I was thinking 8" From water surface to bottom of MH, what do you guys think?

Thanks
Clinton<font size="2" face="Verdana, Helvetica, sans-serif">Hello Clinton.....

considering your viewable space I would go with 175 or 250 watters, you dont need the 400's, and also I would put the lights 12" above the surface

[pocilipora]

Ive started mine at 12" but I plan on lowering them in a couple of weeks. Probably down to 8".

[CHEAPREEF]

Hello Clinton.....

considering your viewable space I would go with 175 or 250 watters, you dont need the 400's, and also I would put the lights 12" above the surface[/QB]<font size="2" face="Verdana, Helvetica, sans-serif">Well i was going to go with 2 400watters,but i like the bright center and low light ends. So i'm keeping my setup the way it is as of now, at least till the bulbs need replacing. So i'm not looking for other lighting options just a height for starting point. I guess i'll try 12" to start and see how everyone likes it. I'll let you guys know how it goes. Thanks for the replys.

Clinton

[ 20 May 2002, 12:16: Message edited by: CHEAPREEF ]