Hey all, I've considered adding a glass shield to my hood in the past and had a couple of questions regarding potency. Since any glass or plexiglass is going to block UV A and UV B rays to a certain degree, the potency is going to be affected. Does being able to move the light closer to the plants offset this? Has anyone done double blind tests on potency with 2 identical grows? Having one with a glass shield and one without? I'd actually prefer to hear from someone who has 2 identical lights with glass shields that has done a grow with one shield removed. Quality and Potency are much more important to me than quantity so I'm not really interested in growth rate differences.
having a glass shield and being air cooled would allow you to have your light closer thus giving you more lumens resulting in higher yeild. as far as the potency being affected by the glass shield i would say it would be so miniscul that you only will be able to tell in a lab if at all.
I Agree. I have seen two clones grow under a 430w hps one had a glass shield and was vented and set at 8-9 inches while the other was at 16+ Inches and there was a very considerable difference in yield. We trimmed a bud that wasn't getting enough light with 3 weeks left of flowering and it was more than what our average top nug weighed the time before without the vented, glass encased hood at the end of the grow.
You can get different types of glass and obviously the one with the fewest impurities would be best. I have heard you can get quartz glass cut to fit and it allows almost 100% of UV-A/B thru. I agree, I think a closer light is more effective than the no-glass higher light.
