Thanks @DemonTrich. I had gotten discouraged because everyone claimed that basically no UV B will make it through the glass and because I have the GE it has to be in an enclosed fixture. It doesn't have the spool that holds the arc tube in place in case it explodes. I am a plumber and I will be installing sprinkler heads in my grow area.
Last question sorry...does this affect calyx to leaf ratio as much as everyone claims? People swear the cmh grows more leaf than Hps.
I hope you don't mind if I chime in here. :-)
The cmh I have been testing since last November and comparing with
Hortilux 600 Super hps and
Hortilux 600 and 400 "blue" mh is a pretty amazing little bulb.
It will flower a plant beautifully in a 2.5' to 3x3 area in my garden. My 600 footprint is a bit larger and deeper though. (For twice the wattage)
It does grow leafier more compact flowers. And it seems to repair and restore health to deficient or over salted leaves better than the hps. Both metal halides also had his quality so it must be the lower intensity and fuller spectrum is better for foliage.
But the enhanced HPS makes bigger denser flowers and a better bud to leaf ratio. So I will continue to use 315 and Super Hps bulbs together.
The uv the 315 adds has made a noticeable difference in potency and complexity and even duration of the high.
Also more color and much frostier. The concentrate producers must love them.