MHs... How High Above The Water?!

[crewdawg1981]

Okay, so I never seem to get the same answer.. just a more common one than others...

How high above the water do the bulbs need to be? I have heard anything between 9-12 inches. I'm trying to work with Dustin on designing my stand and canopy and while I originally wanted to use 12 for proper spread... I might not be able to open my canopy at that height (I think the ceilings in that room are only 8 foot).

Sooo... would it be bad if I had them 10 inches over? Seems like a really small amount to be worried bout it... but.

Thoughts?

 

[frank]

I've got mine sitting right at 10" from the waterline to the middle of the bulb. It's been that way for about 3 years now. However, I do get a bit of temp rise toward the end of the lighting cycle and since I'm not using a canopy, YMMV when it comes to heat build up, etc.

Oh, just for reference, I'm running a single 250w over a 90 corner.

 

[eric b]

Is it over the 90 Gal tank and 175 watts MH that you state in signature line???? What reflectors are you also using???

 

[crewdawg1981]

Well it will be (3) 250w Radiums in Lumenmax Elite reflectors over the future 180

The 175s are only about 7 inches over the water

 

[eric b]

Crewdawg1981;553851 wrote: Well it will be (3) 250w Radiums in Lumenmax Elite reflectors over the future 180

The 175s are only about 7 inches over the water

IMO you should be fine with 250 watt radiums 10" over water.

 

[crewdawg1981]

Schweet.

Thanks guys