skunkd0c
Well-Known Member
my last 2 plants needs 2 lights to fully cover it 1 is not enough, i could use 2x 400w but they quite tall im not too worried about electricity cost of another 400wI have come to believe the common belief that more light in the final weeks = more yields is not true. (most of the time)
I've found about the opposite. Intense lighting was more beneficial during the first 4 weeks for optimal growth to setup the stature of the plant.
I have tilted 2 600s in towards a center 600 with 4 plants under it.. ((hps) - (hps) - (hps)) plants under the center light.. The plants under the two outer lights had finished so I tilted the two outer light inward..
What I found was that the plants did not yield any more than they did with just a single light over them for the final 3 wks.. Maybe a few more grams, but, not anywhere near being a good return on investment.
The exception to that rule was with a long flowering sativa (14+ wks)..
Skundoc.. if i remember right.. you grow some sativas, so, not surprised to hear you are working with some high light levels late in flower.
I think the reason why longer sativas show returns from more light is that
these plants don't go through the wk 5/6 explosion.. they just gradually bulk.. these plants (and sativas in general) seem to yield more with more light later on.. Indica leaning hybrids though (95% of what I see on RIU)... no change. Might as well save on your elec bill and stick with the same light you used earlier in flower.
Different rooms/genetics/etc show different results... This could have been phenomena limited to my past grows.. but the results were clear.
It makes sense though.. Think about when the plant is eating up nutes... wk 2 - wk 5 on your usual hybrid.. Wk 6.7,8.. not much. If you fed the plant enough N through the first 5 wks, they barely even need fed. Unless you fed 1-3-2 through flower.. then it will always look hungry and won't be as clear to see as it was for me.. feeding more like 3-1-2.
If you run recirc hydro then testing ppm through flower would be an easy way to confirm what I said up there and/or see if this is a "truth" that applies to your grow or some bullshit that won't work for you.
I would expect to hear the argument that the plant is not consuming nutes from the nute solution late in flower because it has stored up feed from feeding through the first 5 wks.. To that I would just say that adding light didn't add yields in my garden, whatever the explanation behind it.. no dice.
The fact that the plants are not using many nutes in the final 3 wks seems right in line after seeing that doubling lighting for the final 3 wks did very little for a standard hybrid. If it isn't using nutes.. what does it need more light for?
It's one of those things that is for our mind more so than for the plant... ya know... more is better kinda thing..
personally i have found plants can be started off with just 250's until buds develop then the light can be increased
they do not need much light to start flowering if you have shading issues this maybe a problem
i would not expect dramatic improvement with yield but i would expect some increase when the plants become saturated with light
the colas become as dense as possible
peace