Hood Glass ?

I have a 13x22 1\2 Sus Systems Hood with a 1,000 watt HPS Three feet over plants in a 4x4 tent.I remove heat with a 6 inch CAN FAN 265 CFM. My question is what would be the advantage of taking the glass out of my hood ? Would it increase \ improve light output? , or would I have to raise the light ? making gains negligible ?
Thanks and......J.L..

No gain that I can see or have heard off. Keep it simple.