So I understand that the T8s on the 440 Solar Storm are to be used during the last few weeks of flower. Is it okay to keep them on for the full 12 hours? Or is the percentage of UVB too high for that? (I've read that 5% UVB is okay for 12 hours, 10% 5-6 hours a day, 20% 2 hours a day)

Yes you can run them for the entire lights-on period during that ripening phase. There is also some indication that some early exposure can be helpful so I personally, i.e. this is not the recommendation of CLW) recommend you run them a few days or so when the buds are in the early heavy growth phase and then continually during ripening, because UVB may have a trigger type effect.

I personally have actually run much higher levels of UVB (60 watts mercury vapor UVB lamps, danger, danger Will Robinson!) than provided with the SS440 in an HPS grow all the way through a 10 week cycle with no (at least obvious) deleterious effects. UVB levels in the tropical sun are MUCH higher. I think some experimentation is certainly welcome and safe at the levels provided with the SS440 UVB lamps. IMHO..

Alchemist wrote:Yes you can run them for the entire lights-on period during that ripening phase. There is also some indication that some early exposure can be helpful so I personally, i.e. this is not the recommendation of CLW) recommend you run them a few days or so when the buds are in the early heavy growth phase and then continually during ripening, because UVB may have a trigger type effect.

I personally have actually run much higher levels of UVB (60 watts mercury vapor UVB lamps, danger, danger Will Robinson!) than provided with the SS440 in an HPS grow all the way through a 10 week cycle with no (at least obvious) deleterious effects. UVB levels in the tropical sun are MUCH higher. I think some experimentation is certainly welcome and safe at the levels provided with the SS440 UVB lamps. IMHO..

Thanks for the reply. I'm into week 5 now and the strain is supposed to finish in 9, but I wonder....the hybred seems to be a sative dominant pheno... so just wondering when that heavy growth phase will start....lol I mean, by the time you notice it, it's already been started for a bit...