How much light and when?

[Tumbleweed]

Noob here on first grow. I've got two Amnesia Haze plants in a 4x4 tent, under a Mars 2000 (300 W) LED. I heard on the Dude Grows podcast not to turn the lights up all the way because you want to gradually turn up the lights as you go through the flower stage.

Is this correct? If so, what should my lights be set at now, and when do I start turning it up? Right now I've got the lights about 20 inches over the plants and turned down to 25%. The plants are about 3 weeks old and were just transplanted from solo cups to 1 gal. pots a couple days ago.

[Xena]

You’ll get exactly what you said and I guarantee you’ll get others say 100% right now. It’s personal preference. I have ts1000 @ 80% ~24” just over 2 weeks old (just went up from 75%) and will be 100% by the end of the week.

[YYCannabis]

You need to think of lights as food. The more food you feed, the better she grows. Once your plant has 4 or 5 nodes, go to 100% power and keep it there until you cut her down. Be mindful of height above the canopy so you don’t burn the top leaves. Watch for plant stretching (light too weak) or clawing leaves (too much light)...adjust light accordingly.

Cheers
YYC

[gbauto]

I agree with YY.
Once my plants are about 3 weeks old, I increase my fixtures output to almost full power.
You will need to monitor how the plants respond and adjust the light height.
The idea is as you enter max veg growth, it's important to ramp up the DLI(the total amount of photons of PAR in a daily cycle).
Then, when you flip to 12/12 you will need to increase the intensity to maintain a similar DLI because the lights are on for 6 fewer hours.
As flowering progresses, I do reduce the intensity to about 75%.

[Rwise]

I have 2 MH tws 2000s, both run 100% from the time I drop the seed into the soil, 25" - 30" for sprouting, 18" - 24" for veg, and 12" - 18" for flower. The underlines are where I set mine and let them grow to the light then raise it when they get to close. (or bend, tie down, cut off, whatever)

[SoOrbudgal]

I run 400watt from the wall LEDs have them 30" from 2-3wk old seedlings, 22>18" for veg an flower. I carefully watch for leaf change odd growth.

[SommerVirelli]

As you see, there’s no wrong answer. It’s true tho that plants just don’t need as much light in Veg as they need in flower. They need much more energy in flower than what they received in Veg to get maximum yield. For example, if you Veg at 100% power, then to get the maximum yield from that 100% worth of Veg growth you will need over 100% worth of power to achieve it. So to counter this growers will dial back their lights in Veg so they can reach their potential in flower. If you’re using powerful lights (500+ watts LED) then you should dial down just for the fact that vegging at 100% could be seen as overkill.

[YYCannabis]

I would disagree with this theory. As i stated earlier in this thread, photons are food. Giving them the most light they can handle throughout the grow is best. You will get bigger, better root system at 100% power during veg cycle. Those big roots provide all the sugars and energy to the buds during flower. Purposely starving the plants of photons in veg (causing smaller root growth) is counterproductive to getting bigger buds at harvest.

Just my 2 cents. 😉

[Tumbleweed]

Thanks everyone!
I raised the light a couple inches and bumped it up to 50%. I'll get it up to 100% over the next few days.

Rwise, I was thinking I might buy another MH TWS2000 and add to my tent in time for flower. Are you by chance in a 4x4 as well? Just curious if that would work well? What's with the phone cord that came with my light? Is that to control a second light from the first one or something else?

[Rwise]

Tumbleweed No I have a room dedicated to growing, and I am already thinking I could move these 2 lights apart a few inches and put a third between them, LOL!