The results are in

[skylord]

Correct me if I'm wrong but it wouldn't matter if your testing 2 3 or 4ft bulbs against the MH. Your not reading the par for the entire tank, just the area below the bulb.

Wouldn't testing an area between the two MH bulbs show something quite different for par? It wont change with the T5 over the length of the fixture.

My concern for a test like this is color temp and reflectors.

Scott

[StirCrazy]

Originally Posted by skylord

Correct me if I'm wrong but it wouldn't matter if your testing 2 3 or 4ft bulbs against the MH. Your not reading the par for the entire tank, just the area below the bulb.

Wouldn't testing an area between the two MH bulbs show something quite different for par? It wont change with the T5 over the length of the fixture.

My concern for a test like this is color temp and reflectors.

Scott

yup your right, although we did find the DE250 MH did have an increadably large area of full intensity.

but heres the thing, a MH will effectivly light a 2ftX2ft area (just to pick a size). in this area you will have a center of about 1ftX1ft (At a specific depth) that will be brighter than the other area but only slightly and the dimmer area (if you can call it dimmer) will still have more intensity than a T5 output.

the main think to look at is on deeper tanks, as you go deaper the socalled hot spot of a MH increases in size so you get a wider coverage that is even. where I do think the T5's would be perfect for is shallower coral tanks with lower light types (I am not saying you can grow high light corals under them as we have seen them grow under a NO bulb befor) or I think they would be a very smart purchase for a FOWLR where you just want the color to make the fish pop as it would be even everywhere. I am not claiming that MH is a nice even lighting, but rather people seam to think if you are not right under the bulb there is no output, where in reality you can't be more wrong about that. My old tank (1/2 of a 180) hade over 350 units of par in the corner on the bottom (24" +6" of air and offset 4" behind the bulb and 12" to the side) with the lighting I had then, the T5's didn't make that directly under the bulb at 6.5"

Steve

[mr_alberta]

That's interesting. What type of reflector were the t5's using? Or was this bulb only (i.e. no reflectors or glass in the case of the MH HQI).