Metal Halide lighting Question

[Swirlygig]

I was wondering...From the water surface to the base/bottom of my VHO endcap/bulb it is about 8".

To the top of my hood where I would mount a Halide bulb it is 11". Is this too short/close to the water to install a Metal Halide Retro?

I do not have a chiller so I am concerned about water temperature...I am running 760Watts of VHO (6 bulbs)...I would be switching to 3 X 250W MH and 2 VHO actinics...

What sort of temp difference can I expect?

Thanks,

Jeff

 

[skippy823]

big temp diff. i run mine frombulb to water about 13 inches with a chiller and seperate ac unit in the room with the tank without the chiller on the tank reaches temp to about 82-83 degrees

 

[skinnyjoe1976]

my 175 is about 6" off with a closed canopy and (4) vho's. no chiller just a fan running over the sump and tank stays at 80.

 

[markandkristen]

i used a clip on fan from walmart on mine with good success.. my temp went up in my tanks from adding powerheads like seio 2600s

when i ran tunzee 6100s than my temp never got above 80 with the fans going and the 250 watt halides

 

[JUICE!]

I'm burning 3 400 watt metal halides over my 125G at work and it stays under 81 degrees. there are 4" fans next to each bulb that expel hot air, and my office stays pretty cold (75 degrees or so)

and the bulbs are pretty high! 12-18 inches

my 220G at home runs about 84 degrees without the chiller, but the halides are maybe 6" off the water in that tank.

you ought to consider picking up a second hand chiller Jeff. you can scoop up a 1/4 horse for around $250 used. even if you don't need it, it would be a good backup in case your fans quit or your halides get stuck on....or the a/c goes out in your house for a couple days

a pretty cheap insurance policy if you consider how much money is swimming in the tank, or growing on your rocks!

 

[chrisstie]

The only concern about running them too close to water is that those bulbs are hot and the water is cool. Occasionally water splashed on the bulb (fish freaking out, whatever causes it) can cause the bulb to pop so you want to be able to avoid that.

 

[cham]

I've always run my MH's 5 to 6" above waters surface with no chiller.

Fans do the trick.

 

[Swirlygig]

Well, I think there are a few things I can do to keep the temp down cheap...fans!

I bought a 3X250W HID MH retro kit today...comes prewired and all I need to do is mount em