Excellent independent review of the Radion diffusers

[Larry L]

do you think the diffuser will increase the spread enough to cover the 34 inch length for the time being?

I run two XR15's over a 36" x 24" tank (18" deep). When I added the diffusers, I didn't find that it changed the spread at all, it just made the distribution of light more uniform over the same general area of coverage (less disco ball effect, less hot spot).