UV only helps if it's 285-315nm. Growl uses a 390nm or 410nm UV (which really isn't UV), which does nothing for THC production. It's just a marketing gimmick.
On another note, are you going to continue on with the HGL vs Growl competition? I was very interested to see the results. Being that the Penetrator 126W was already diong better than the Doberman, what made you buy Spectra lights instead? Irish Boy did that a long time ago, and after making the switch to GLH, training his plants, picking high yielders, removing the glass, etc... he still wasn't able to match his GPW from the HGL light with no training, no trying, just growing. I just don't understand why so many people seem to throw the superior light aside and instead opt to try yet another, and not just another light, but one that's proven to deliver worse results... If I were going LED, I'd only want the best...
