How close is too close??

[ryebread]

Currently building my canopy for my 120g reef.
I messed it up already.
What I need to know is how close my MH bulbs can be to the waters surface before I need to worry about them. They are 250 watters.
If a fish jumps and splashes around will these bulbs blow up?
This was not a good time for me to have fubar'd the canopy and I am disappointed in myself for it........I can build another one I guess but, I was nearly finished with this one.......
The plan was to have a canopy that was 18" tall......now it is 9" tall and I am worried about the clearance.
Glass Tops?

 

[ryebread]

Do you think that it might be possible for me to build an extension of some type?
I could whip together an assembly that would raise the canopy up another 4" pretty easily I suspect. I think I might like to try that instead of starting over.........my bulbs are mounted and everything.....fans, ballast, ugh.

 

[a&m aggie 04']

the way my canopy is built, it is 2 pieces hinged together so that i can open it up and the lights go up with the top piece. maybe you could use the part you built for the top part. heres a few pics

 

[a&m aggie 04']

and closed

 

[plum70rt]

got a pic of what you got so far?, I have acrylic covers but I dont use them, too much heat build up

 

[ryebread]

No pix as of right now.....I am at my apartment and the canopy is being built at my house. Long story.
Pics will be here soon.

 

[hairtrigger]

I heard MH lights were supposed to be 12-18 inches from the water's surface.

 

[broncofish]

I know Jamesurq ran 250watters over his 90g, and they were like 6" off the water, and he never had any problems.

 

[broomer5]

Don't feel bad Rye ... I built mine too high and had to chop it down LOL.
If you're happy with the looks of the 9" canopy - you can build and extension for it. Just extend it up 6 inches or so.
Make it a total of 15" in height, mount your MH 3-4" under the canopies top - that'll put them at 11-12" from water surface.
You could run a piece of wood trim around the extension joint, and it might look okay.
Sometimes DIY means DIY more than once

 

[ryebread]

Originally posted by broncofish
I know Jamesurq ran 250watters over his 90g, and they were like 6" off the water, and he never had any problems.
I seem to specifically remember an unbelievable algae problem.

 

[marinemarty]

Hi Rye, Have you seen any evidence that algea growth is related to the distance from which the bulbs are from the water?? I just thought it was a heat and splash issue. Thanks
Martin

 

[plum70rt]

this is how I munted my MH, my canopy is 12 inchs high,bulbs are 8 inchs from water surface,no problems at all, also I have heard of one guy that I know that had a bulb burst because of a water splash, everthing on that side of tank DOA,

 

[ryebread]

No proof Martin.........just an observation.

 

[iceburger]

120 gallon???.............oh by the way, hi

 

[ryebread]

Hey Brian! How are things? Hope to hear from ya.
Had to go with a 120 baby! I have been shooting pics for a guys website and he gave me a whole bunch of store credit in return.

 

[johnnysalt]

PLUM,
(or anyone else!)
I like your setup.....I just got 2 175w mh setups....I have a diy canopy like yours too. mine does not have a back....should i cut a hole in the back and stick a fan in the canopy like you have? bulb is about 6 or 7" from water. I have one light installed in there now and it's 85 degrees in there.....i guess it would get up to 95 or 100 when i add the other one....how hot would you let it get before you added a fan?
thanks,
John

 

[ryebread]

I would add the fans right now. At least two of them. If your tank is already 85 degrees, you may have to consider running a chiller to help cool it down once you add the other bulb. That is one hot tank.

 

[johnnysalt]

Rye,
it's 85 in the canopy, not the tank temp! I'll update this post with the tank water temp when it hits its highest temp in an hour or so.
so again, what is "too hot" in the canopy for you?
john

 

[sandman_rsr]

Hey Rye
got my M.H about 8 inchs from the water when its full lol and everything has been great for the last month or so and i try my best not to splash water on them but it has happend from shaking the net and so far no pow!!!!!!!! lol

 

[broncofish]

Originally posted by nolofinwe
does anybody have any reliable anecdotal evidence of bulbs exploding?
Not with fish tanks, but I had an albino pac man frog for about three years. In his terrarium I had an automatic DIY misting sytem. The line poped off sprayed water all over his light bulb.... ....Came home to a dead albino buddy I learned my lesson from that and use plastic clamps on everything.