Great. I have noticed that the leaves start to sag the last couple of hours in the day in my garden.
*BTW, I too am an old guy with a little time, and resources and patience to devote to growing. We gotta help each other!
So in post #66 you said, “It is about the same, nothing noticeably different, a day or two on either side maybe?” So once you determine the optimal DLI for you plant, then if you take 6 hours or 12 hours to deliver that optimal DLI, it doesn’t really make that much difference in finish time or yield?
You got it. That is how I am going to be running plants from now on. Figure out how much light they can use per day and keep it around that level. Then use that information to maximize the next run with that strain. It has saved me a lot in power which makes it worthwhile.
Ok, vertical-ish.
There are some things in this that makes sense to me and some that dont.
Dont: theres a paper thats been thrown around more than a few times on her that shows a graph on light-levels, showing that over 800 mmols the efficiency of photosynthesis starts dropping quite a lot. Sadly i dont know all the details, just looking at the graph really, and its possible that the whole paper is based on 12/12 and doesnt really factor in optimal DLI, just that too much light per cycle is no bueno.
Does: if i understand plant physiology correctly but please correct me if im wrong: the plant doesnt really do the growing during the day, it grows during the night. During the day it photosynthesize sugars, breathing CO2. These same sugars are then spent or "eaten" by the plant during night time when the energy gained thru burning them so the plant can grow. This process creates CO2, as quoted in many GML episodes. So you also get CO2 without having to use tanks or burners. Car analogy: it spends the day "filling up gas" and the night "making miles", more time "driving" more miles.
Torontoke (i think?) was the one who quoted seriously reduced flowering times with same yields as 12/12 using 8/16 hours. If youre running your strains the same amounts of weeks as before increased yields might be the other side of the same coin.
It doesn't say the light cycle used to determine those numbers. Most likely you are correct that it was based on 12/12 light schedule.
800 ppfd for 12 hours is around 36 DLI which sounds about right. Going over that may give you small increases but nothing like the increases seen from 10-20 DLI which is usually when the plant is taking off in veg.
Do read up on dark cycle reactions. Calvin cycle. All that has to do with photosynthesis. Fine tune everything.
For your car analogy also consider that driving at night may get you to your destination faster, with less gas, etc, because there is less traffic on the road and you are able to drive more efficiently.
In my opinion, outside of scientific studies, using supplemental CO2 generation is somewhat unnecessary as you can get more CO2 to the plant with increased airflow. That also helps with the heat. If you want more then go hangout in the grow area and sing to your plants
@torontoke was indeed the guy who started posting about drastically reducing lights on times. He took a lot of grief for it from people who were terrified of anything that challenged their notions about how plants 'are supposed to grow'.
One big difference between his observations and those of
@Slinging PAR is that he said his plants finished much faster and slinging PAR said he found otherwise. No one has to be wrong, I'm curious about why the difference might exist.
It is difficult to improve if you aren't willing to try new things. There will always be naysayers afraid to consider anything outside of their knowledge-base and comfort zones. The great thing about the internet is it comes with tools that help to ignore ignorance!
Many different things could explain the difference in finishing times. Main ones I can think of is when the grower chooses to harvest, tastes are different, different strains, etc. I have also been running these strains for a long time (even under other lighting) and am confident to say that I am close to if not reaching the potential for these strains. You can't replace or discount experience.