diffuser

Has anyone ever used a fluorescent light diffuser and some acrylic rod to build a DIY diffuser for an AI Hydra?

I have (1) Kessil AP700, (1) canopy mount, and (2) major diffusers for sale. The light works great without any issues and does not have any visible markings, scratches, etc. on it. No salt spray on them as they are currently hung 16" over my tank. I'm keeping one of the lights to pair with a T5...

So inside of the canopy (which measures 36" x 36" OD) I have 4 SB reef lights and a 250w Radium w/ Spyder reflectors. I want to put a sheet of wither polycarbonate or glass over the bottom, inside the canopy to either a.) help diffuse the light into a uniform source (I do know MH's don't need...