Uncle Ben
Well-Known Member
As I watch the different flower rooms progress(all have a different spectrum) I start to draw a somewhat new conclusion to it all. I bet there will be many who agree with this thought. I'm starting to realize that the best way to flower a plant is to start the 12/12 under some kind of blue heavy light whether it be a MH/CMH or what have you. Then about half way through flower, switch to a red heavy light like HPS all the while combining both spectra with additional deep red light.
I'm finding that plants started under MH at 12/12 produce healthier and more abundant flower sites as opposed to HPS. But plants finished under MH tend to be airier and leafier than HPS. Adding blue light to HPS will help with the trich production the way MH do.
So far I've been having the best results starting the 12/12 cycle under MH and when the plants start bulking, that is the best time to switch to a red heavy spectrum. This really makes sense when you think about it because during the first half of the budding cylce there is still quite a bit of veg going on, leaf growth, root growth, etc. It's when the flowers need to start bulking that it's best to make your spectrum more red dominant.
This holds true in the natural cycle of things. In late summer when buds start forming, there is still quite a bit of blue light in the Sun's spectrum. Come late fall, there is hardly any blue and the spectrum 75% on the red side of the spectrum. This is the time when buds start packing on the weight.
In all the trials I've done, i.e. finishing under blue light vs. red, initiating flowering under red light vs. blue, this has been the most successful.
I encourage all of you that have access to both types of lighting to start the 12/12 cycle under MH and about half way through the cycle when the buds want to start putting on weight, switch to a higher power HPS. This seems to be the final consensus. If you have access to any deep red light sources to add them to both light sources as deep red seems to encourage both the photosynthesis process(leaf growth) AND encourage the Pf to Pfr flower cycle where the buds really start to put on the weight.
To me, it seems that yellow light discourages bud set and flower formation, but encourages the bulk/weight part of the ripening cycle. Since HPS are mostly yellow/orange light, I would discourage the use of them until the final stage or last 4-5 weeks of flowering and go with MH(K temp doesn't seem to make a difference) for the first 1-4 weeks of flowering.
I smell BS......