Light Hood DIY

Mad_Dog · 02-27-2003, 09:50 PM

Building a new hood totally enclosed to sit atop a 55 gal. w/ 2 175w MH and 4 VHO tubes. How high should the lights be above water level, and do I use a lense on the hood, a glass top on the tank, or neither ??? help...

tdwyatt · 02-27-2003, 10:01 PM

oz reef dyi, Scroll down the page and check out some of the links

Mad_Dog · 02-27-2003, 11:58 PM

Nice link: still the question remains - how high - and what if any Lense ?

Stang69 · 02-28-2003, 12:52 AM

My 175's and VHO's are about 7-8 inches off the water with no glass if that helps

cyberchef · 02-28-2003, 01:08 AM

Most people consider 7" - 9" of clearance between the surface of the water and the MH bulbs to be sufficient. Regular (mogul based) MH bulbs do not need a glass lense (the mogul based lights have a UV filter coating on the bulbs) or cover unless your tank splashes water. HQI bulbs need a UV filtereing glass lense to protect the tank from the UV light as the bulbs themselves have no Uv coating. You will also need some sort of openings in the hood to allow for air circulation, a fan or 2 might not be a bad idea either, to dissapate the heat, or else a nice chiller to deal with the temp of the tank rising... As long as splashing water is not a problem, then it's best to leave the top of the tank uncovered to allow for gas exchange (CO2 and O2) between the tank water and the air.