t5 beam angle?

[shrimphead]

Hi, i've been searching the internet for a while now for what size beam angle do t5s produce with a reflector. I know it depends on the actual reflector but an average beam angle figure will do me. (i'm guessing between 80 and 140?) I'm just trying to work out the height i would need to set the unit and the coverage of 4 t5's over a tank 40cm deep, 90cm wide and x long (length depends on length of t5s) and all the t5 bulbs would be different spectrum's so i need all 4 to blend together and also reach both sides of the tank.
(I'm making a sketch on google sketchup to see the beam angles over the tank)

[Ranger Daryl]

Florescent bulbs by themselves produce 360 degrees of light. The reflectors in my 6 bulb fixture are somewhere between 80 and 90 degrees. I don't find that the height of my fixture has much on effect on my coverage. I'm running a 36" light over a 48" tank the light is about 8" above the water and I get good coverage all the way around.

[shrimphead]

80 to 90 ok i'll take that on board, but i don't understand why you don't think the height of the fixture effects the coverage? the higher you raise the unit the more coverage it will have but less intensity