[StirCrazy]

Originally Posted by fkshiu

But really, I don't see how there should much difference at all in the light produced by DE and SE bulbs notwithstanding the extra UV shield required for DEs. If you look at an SE bulb, it's pretty much just a jacketed DE bulb.

it is and it isn't, the bulb is actualy a different design for the lighting element, not sure the exact differances, but I know operating temp is one as the outer glass and the gass inside it on a SE act as an insulater so the SE actualy burns a bit hotter, so maybe it creates a bit more efficiency?

the increase in PAR from a DE to a SE is small, and isn't realy the important part, rather the way a SE desperses that PAR over a larger area with out losing as much intensity is what I like. for example, you can light a 2X2 area with a 250 DE. with a 250 SE you could light a 3X2 area with pretty much the same effect on the bottom. Now having said that I ran two 250 watt SE's on a 3X2 area driven by M80 ballasts because I like light and lots of it

so there are aplications for both, if I am making somthing with out a hood and I wanted a nice compact fixture I would probably use DE's but if I had to room for a hood I would go SE's. Presently I am concidering putting two 250watt SE fixtures on a 30 gal tank. but I am hesitating in setting it up as I realy want to go bigger, but not sure if I have the space for bigger.

Steve