Slightly worse - Likely its tempered glass, and not "optically perfect". But the benefits of being able to get the plants closer to the light source and cool the light fixture is well worth it. Plus if the bulb shatters you have something (besides your plants) to catch the burning shrapnel
Tokudai Reviewed by Tokudai on . Glass between light and plants Is a piece of glass between my hps lamp and my plants better or worse for light production? Rating: 5