Which paint for grow room?

X3 on the Killz
or
-Latex Base DryLok masonry waterproofer if its in a basement or something like that.

Dead flat white can be as high as 90% reflective, gloss as low as 50%. Matte would be somewhere between. Mylar is 97% as a point of reference (but has poor diffusion). I have doubts about a manufacturer's claim of 95% for the roof coating. Flat paints are hard to clean, and mark easily.

You can buy fungal killer packets for a few bucks that can be mixed into any paint.