What are the benefits to having a 18/6 light cycle, and what are the benefits of leaving them on all the time?
About the only way i've been able to look at this subject is cost wise, hence my reasons for 18/6 Its natural for plants to sleep during the night
thats just what i said but i also know plants dont grow very much at all at night so if u have it on all the time naturally the entire process will be sped up like 33% and i know they also do fine in 24, but whatever i guess just pick up experience right? im sure it hasa different effect on each strain anyway.
I found this useful- "It's been established for many many many years now that cannabis is a C3 plant. It does not need a dark period. C3 plants gather CO2 only during the light period when they are photosynthesizing. As long as the light is on, C3 plants gather and use CO2 for photosynthesis. Some growers practice a version of anthropomorphism with their plants. They believe that since people need rest, plants do as well. Concerning cannabis, this is not true. Every grower can make a personal choice about light cycle. They can save on their electric bill or prolong ballast/bulb life. 18/6 can be less of a "shock" when changing over to 12/12 for flowering than 24/0 or heat issues can be addressed by fewer hours of light, but basic botany has proven long ago that cannabis needs no dark period. Marijuana plants photosynthesize as long as they receive light as well as water, air, nutrients and suitable temperature. Photosynthesis is the process in which plants use the energy from light (primarily in the blue and red spectrum's) to combine carbon dioxide (CO2) from the air and water (H2O) to make sugar while releasing oxygen to the air. Plants use sugars continuously to fuel metabolic processes (living) as well as for tissue building. The plant combines nitrogen (N) with the sugar to make amino acids, the building blocks of proteins. They are the substance of plant tissue. When the light is off, the plant's metabolic processes, respiration and growth, continue. The plant can photosynthesize continuously so it produces the most energy and growth when the light is on, continuously. Continuous light does not stress the plant, which reacts somewhat mechanistically to it. Plants under an 18-6 light-dark regimen are producing sugar only three quarters of the time. They are thus growing at only 75% of their potential. Leaving the light on continuously will result in bigger plants, faster, which leads to higher yields."..............ED ROSENTHAL ------------------------------------------------------------- "The following information is straight from Greg Green's "The Cannabis Grow Bible" Cannabis is a light demanding plant. Professional growers keep the light on their plants using the 24/0 photoperiod for this reason. Plants that grow under 24/0 flourish and do not need a quantity of darkness in order to rest and perform photosynthesis properly. Plants that are grown in optimal conditions under 24/0 light regime grow vigorusly and the benefits of a 24/0 photoperiod can be seen actively in the results. More nodes are formed, more branches are created, leaf numbers increase, the plant is growing at its finest. Some growers opt to use 18/6 as their photoperiod. This is 18 hours of light, six hours of darkness light regime. Under these conditions the plant will grow quite naturally but not as vigorously as the 24/0 photoperiod. The 18/6 photoperiod expels 3/4 the amount of light that a 24/0 photoperiod does. Although this does not mean that a plant produces 1/4 less leaves,branches and nodes under the 18/6 photoperiod, it certainly does show the correlation between light and cannabis growth. As we have said already, cannabis is a light demanding plant. There are no problems associated with 24/0 and although some have attributed cannabis sexual dysfunction (the hermaphrodite conditon) to 18/6 photoperiod these problems are actually the result of heat stress. A 24/0 photoperiod requires that your grow room temperature be kept well monitored. The 18/6 option is cheaper to run. You use a quarter less electricity and this will have an impact on your electricity bill. Also the 18/6 photoperiod will generally extend the bulb's lifespan. During the 6 hours of darkness the grow room is allowed to cool down for this period but a well maintained good grow room setup should not require a cooling down period. 24/0 and 18/6 both share the same problem though. Once you start the photoperiod you should keep that way especially when the plants near maturity (the preflowering stage). An irregular photoperiod can cause more males than females to develop. It can also cause sexual dysfunction to appear. Whether you choose 24/0 or 18/6 as your vegetative photoperiod try to keep that photoperiod unitl your plants are mature enough to express their sex." Sooo what light cycle do you use? And why?
Even that is debatable. Some proponents of 24/0 believe what Leprosy said: They claim that you might save more per month, but the growth will be slower so you end up spending the same if not more money under 18/6, plus more time, to get the plant to the same size that 24/0 did quicker. Not saying either is correct, just how some look at the issue. There is one practical/logistical benefit to 18/6, if you need it: if you have issues controlling heat then you can go dark during the warmest part of the day to help with your temp issue.
this was a concern of mine as well so thats why i plan to start with 24/0 then switch to 18/6 a couple weeks before flowering and then go 24 hrs dark right before I go 12/12
I have tried both and found results to be near the same. I was using t5 HO fluoros. I guess this is one thing that either way, you can't really make a bad decision.
Ok this is a schedule I didnt see mentioned, 20/4. I read a thread awhile back with this debate and some poster said he grew 3 batches of clones under all 3 light cycles, 18/6 24/0 and 20/4. He rated 20/4 as 100% since it was the most yield and quality. 18/6 was around 92% based on 20/4 being 100%. 24/0 was in the 80% range. Even though I have seen the studies and such, I still feel more comfortable giving the plants some night period.
Me too. The thing is, though, it's all anecdotal -- neither of us did a scientific study with large sample sizes and control groups and precise measurements recorded and submitted to statistical analysis and such, we just tried it maybe a few times on a few plants each and that was it. The thing is, there are others who also tried it in small cases and did see a difference, or so they thought -- and even they are divided between which led to the best results. That's basically splitting the difference, again works well and some growers think by splitting the difference between 18/6 and 24/0 that they are getting the best of both worlds or something. Any schedule with at least 18 hours of uninterrupted light per 24 is good for vegging. From there you just need to find something that feels right for you, then grow on.
more light = more time for the plant to grow.. thus 24/0 is the best. why do you think Alaska grows those huge vegetables? /thread, look at those huge Alaskan vegetables for proof.
i been doin 24/0 mostly and i doing great, other people do great doing other things, marijuana is great in general so its tough for peopel to fuck it up too much. simple as that.