36 long x 20 w x 20 h. Sky is placed directly in the middle with 10 1/2 inches from end of sky to the glass. Mounted on an XR arm at 9 inch high off the water.
I agree, maybe raising the light will give you a better spread. Do you have a Par meter? If will help you when converting from a hybrid to strictly LED's.
Also agree with higher. I have a 36x22x24 and was not happy with the coverage at 9". I found 12" with a slight backward tilt to be ideal. The tilt not only reduces forward glare but also helps to illuminate the aquascape more uniformly. Par measurement comparison here: https://www.reef2reef.com/threads/its-here-sky.849993/