minimum distance for 250 hqi's?


New member
How close to the water surface can I be with 250 hqi's? I'm building a new hood so I would like to know how tall to make it. Btw it's a standard 85g tank.


New member
I'd say you typically don't want them any closer than 6". This is mostly due to heat issues. I would go with 8" though as the reflectors for HQI's are usually pretty efficient and you don't really need to be any closer.


In Memoriam
Mine are 5-6" above the water.

The answer though lies in what type of reflector you are using, and the area you are trying to illuminate. The lower, the better (no lower than 5" though id say), but the smaller area you will light... but of course this depends on the height of the tank as well.

Id say try to get them as low as possible... 6" above the water is a good goal, as long as you cover the area you intend to. Rather than raise the light if the light doesnt spread enough, you can also use wider reflectors like the SLS lumenmax3, or the Lumenarc DE pendants.