LED Grow Light

Why We Don’t Recommend 6/2 Light Schedule-Part II

As we discussed earlier, we’re always willing to keep an open mind. We have showed a few possible advantages in the last blog, let’s move on to the disvantage now:

Disadvantages Of A 6-2 Schedule

The primary disadvantages of this lighting schedule are increased complexity and more stress on your plants when you switch from this 6/2 vegging schedule to the flowering schedule.

More Complicated

Having your lights come on and turn off 6 times a day is more complicated than doing it only twice a day. In fact, many timers are only able to turn them on and off once per day. Even the best timer for grow lights is unlikely to have this function. Few timers would even be able to handle a 6/2 schedule.

This means you would have to get a timer that can turn the lights off and on multiple times throughout a single day. You would also have to set up everything correctly so that the lights come on and turn off when they should.

And you’ll definitely need a timer—don’t even think of running this schedule while manually turning your lights on and off.

Naturally, you may want to program your cooling equipment to run concurrently with the lights. Or to increase in output when the lights are on and run at a lower setting when they are off.

Stress When Switching To Flowering Schedule

Switching from vegging to flowering is a bit unusual with a 6/2 schedule, because the length of time the lights are on continuously increases, instead of decreasing as it usually does.

If you use the standard 18/6 lighting schedule (or 20/4 or 24/0), the daylight period gets shorter when you switch to the 12/12 flowering schedule. But when you switch from a 6/2 schedule to bloom, the continuous daylight period actually gets longer, doubling from 6 hours to 12.

Like most of the benefits of this lighting schedule listed above, this drawback is also not proven. There are simply reports from growers who have seen their plants take much more time to adjust to the bloom schedule and to enter the flowering phase of growth.

Most likely, this will not cause a huge impact, but it is worth taking into account, if you are considering the 6/2 daytime breakdown.

One thing you could do to minimize any effects is to first change to a 10/2 cycle toward the end of vegging, before flipping all the way to the bloom schedule.

This will help ease the transition and has the added benefit of giving your plants an additional 2 hours per day of daylight at a time when growth is really taking off. This means they will start growing buds sooner. 

Is It Worth Trying?

This is the big question. Is it worth trying the 6/2 vegging timetable?

The possible benefits aren’t huge, most of the benefits are anecdotal only and have not been proven, and it’s going to be more work for you. Just stick with the 18/6 timetable that is easier to implement and has been proven to work well.

It is additionally worth remembering that plants in nature also live by the 18/6 (or a similar) schedule. They get their daylight in one continuous period, not broken up into 3. Plants have evolved to work with that.

All that said, using the 6/2 schedule is unlikely to have any major negative effects and it could possibly result in some faster growth. If you’re curious and don’t mind the extra work of getting it set up and ensuring it is running properly, there is no real harm in trying.

In fact, since there are a lot of questions online about the 6/2, but there are very few actual grower reports, you could document your results and help a lot of people.

What is really needed is a direct comparison growing the same plants under the same conditions in parallel, with only the light schedule being different. That could answer the question once and for all, which one works better.

6/2 Cannabis Lighting Schedule: Final Thoughts

Running your grow lights for 6 hours at a time, followed by 2 hours of darkness, is intriguing. No doubt about that.

But overall, we don’t feel it is worth actually trying, unless you have the spare time and capacity to do it. If you’re just trying to get a grow going and get a good yield, there’s already enough to worry about. Why complicate matters further for what will, at best, result in slightly faster veg growth?

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