Which uvb bulb are you speaking of? Reptile lights? All the heavy UV bulbs I've seen are low wattage which from what I've seen means you have to have the bulbs very close( which isn't very practical) to have ANY effect ...... on elevated thc/terps levels.... But that's not all I'm trying to accomplish. The plant sensitivity curve doesn't show a whole lot of photosynthesis under 350nm, uvb is 280-315nm. The idea w uvb is to give your plant short exposures to it in the last couple weeks- studies show that's all that's required to stress your plant to increase potency.... Like you said we're trying to mimic the sun UV light is violet, I'm trying to add BLUE light to bring a mostly orange/red spectrum (HPS) closer to the suns balnce of blue/red. Blue light signals stomatal opening -among other things.... Plants have a lot more light harvesting pigments than chlorophyll a/b , see the plant sensitivity curve below.... I thought the same thing as you MH didn't put off a whole lot of UV which is why I initially was gonna go w the cmh as supplementary but that not the case at all. It turns out reg MH puts out a lot more UV than the cmh coming close to the sun in terms of its percentage same w blue light scroll down to the chart at bottom it even has sunlight to compare. I take it you didn't click the link it breaks it all down. It's done by a university so should be legit
And that's just a standard GE mh not a specialized spectrum bulb there's mh that are shifted much further to the blue/violet end of the spectrum (see below). As I was saying though you have to be careful w uvb too much causes plant damage. I've got a 1000w coralvue MH bulb 20 000kelvin which is purple as fuck but it literally puts pinholes in leaves which get bigger the longer the plants exposed eventually burning your plant to a crisp. I also have/had a few of the
solistek 10ks which are more of any icy blue color overall. It's all about synergy tho getting as close to the suns spectrum as possible which is why cmh are great as a standalone- they're very close see the CRI. Hope that makes sense I'm a fuckin scatter brain lol:D the last pic is
hortilux reg and blue