I have been encouraged to start another thread with the purpose of looking beyond the purpose of the trichome and under what condition and how the trichome evolves during the maturation process. The premise I would like to put forward is to look more in depth into the role the UV light plays. There is a significant body of evidence that has shown that the potency of your babies will be improved with UV light a trade off with lumens, but an improvement of the concentration of THC why? Because it is the UV light that breaks down the precursors in the trichomes to THC. This is a little out there so to speak because we have all be told that the HPS is the flowering light when in fact .it produces NO favourable UV light. So while a MH bulb is lower on the lumens scale, it has an abundance of favourable UV light. This is a post that TheBigBad made on 05-21-07 ive read a bunch on how plants grown outside is stronger than the same strain grown indoors. and how UV rays are what cause this. UVB are mostly responsible as they are the stronger of the UVB rays. UVB is what you get sunburns/tans from. the plant makes resin to fight off the UV rays, so outside makes for stronger pot. assumeing all that is right, if you added a UVB light source to a grow room where it would just come on for alil while each day of the flowering phase you might be able to get stronger buds indoors. and if that did work whos to say by makeing the light stay on alil longer each day than the day before the plant wouldnt just go crazy and turn into a huge pile of THC??? lol anywhoo, what do yall think? worth a shot or not? That thread stalled and was last posted on in August. possibly the most authoritative piece that I have found so far is Pate, D.W., 1994. Chemical ecology of Cannabis. Journal of the International Hemp Association 2: 29, 32-37. This paper is widely referenced in future documentation so just as I do in my professional work .I like to stick with what the ganja research fraternity takes as somewhat of an authoritative piece. As a little of an aside, this may be valuable in the discussion relating to the purpose of resin in regards to this, it references anti-dessication (i.e., THC concentration higher in xeric conditions), antimicrobial, antifungal, antifeedant *i.e., chemical and physical deterrent) and UV-B pigmentation roles. But thats another topic. I want to look at what factors might best guide us in further maximizing our resin production and thereby potentially, our potency. In this regard, I take from this paper (and the unavoidable tangential research .), the following: cannabinoids are present in glands throughout the plant in two forms stalked and not stalked; the density of glands increases as you move up the plant (uncertain whether or not this is a function of maturity or structural difference more study needed) in one study, the THC generally increased as locations became less favorable for plant growth, suggesting increased plant stress enhanced delta-9-THC production cannabinoids also may function in the role of UVB protection (another biological stress-inducer), which may be functionally analogous to human skin pigmentation (again more study needed to understand and resolve current information). colour rendering Index (CRI) with a maximum value of 100 (i.e., that of outdoor daylight) only comparable with lights on the same temperature (i.e., 2700K, or 6500K, etc.). For example it is un-instructive to compare identical wattage CRI (70 vs. 20) of MH (4500K) vs. HPS (2700K) recent developments in LPS (Low pressure sodium) might provide some better solutions Pate (1983) and Lydon et al (1987) both demonstrated that under conditions of high UV-B exposure, drug-type Cannabis produces significantly greater quantities of THC. The following are a couple of excerpts from a post entitled UV and its effects (BC Growers Association) .from 1999 .. http://www.geocities.com/SunsetStrip/amphitheatre/5796/uv.htm Growers use two or more 20 minute UV light treatments during the day cycle. Metal halide produce the best potent weed less lumens for the money but better smoke. After years of testing with some friends who did want to keep THEIR recipe (more hps) i foung there weed to be harsh, full of CBD, make me eat and sleep, only good to sell to someone else taht you dislike. The blue spectrum will give you a final product that have everything included :taste without curing, potency and yield, To be effective a ratio of 2 MH for 1 hps at the most.(hps) Hps alone can produce a cash crop but not a connaisseur crop. Et Voila... Q1. if UV in ionisers is used for odour control, will high UV light conditions (high altitudes) also influence odour which has been postulated to have important functionality in the life cycle of cannabis? Q2. should/could we maybe consider the introduction of a highly limited level of exposure to UVB to enhance resin production while within the limited of phytological degradation? Q3. do we need to take a closer look at the true comparison of the growth potential/potency of using HPS vs. MH vs. MV lights? Have we been incurring a limitation to potency by using HPS lighting for flowering?