Light Intensity during Flowering

Indoor Growing
1

Curious about what light intensity you guys give during flower.

They’re about 1/3rd into the flower cycle I’m guessing, and today I noticed that my buds have grown significantly over the last few days since I lowered light intensity by about half.
Now I’m wondering what’s up…

This poll is for LED quantumboard type lights only, with dimmer knob.

Only vote if you are happy with the results you’re getting.

How much light intensity do you give your plants throughout their entire flowering cycle?
  • Full blast, start to finish.
  • Some days full blast, some days dimmed.
  • Sunrise and sunset type of dimming with full blast a few hours every day.
  • Always dimmed.

0 voters

10 Likes
2

very interesting your relate, about a month ago, i bought a 1 more led to my flowering tent, and i was with the lights very next of top buds. I noticed that all of a sudden it seemed that flowering was stuck or very slow.

2 days ago, I raised my leds as much as possible, to increase the distance and decrease the light intensity.
It seems that now the plants are different, they started to develop again and the leaves were facing upwards, as if they were praying, something that hadn’t happened since I increased the flora LEDs.

6 Likes
3

Yeah, same happened to me, I thought: “Oh they’re really flowering now, let’s blast them!”
But nope, they slowed…

4 Likes
4

sounds like it may be due to natural lower light levels during the later part of the year outside.

2 Likes
5

I used to run HPS in flowering with great results. I’ve switched. I don’t run quantum type boards. My LEDs are light bars and I’ve been running them at 100% for the last few grows. I’ve had some bleaching, cal-mag issues, and other “plant struggling” problems that are making me think I’m just overdoing the lighting. I’ve reduced to 75% and see initially that growth seems to be picking up again.

6 Likes
6

Thank you for sharing, I was just thinking about that, many people may be running into trouble simply due to too strong light, meanwhile obsessing over soil, PH and ferts, etc. while that’s all fine perhaps.

Light with a dimmer takes half a second to adjust, so maybe lower that first, before changing anything else.

1 Like
7

Really should go by the daily light interval, DLI, based on the number of light hours.

6 Likes
8

Well I won’t vote but I will say I had 3 plants a little further in flower They had gradually been introduced to 100 percent lighting. However I ended up flipping another plant to flower when they were already blasted and I’m more impressed with that plant could be a pheno thing though

2 Likes
9

It depends on your lights but most LED quality lights are too bright even supplementing with CO2 at full power. I’d run them around 600 and step it up slowly to maybe 800 if no CO2. If your top buds are growing spindly and the lowers look better you know you’re too bright. Each cultivar is going to be different too of course. Really you’d need to run a specific strain and test it out. There’s a lot of variables.

7 Likes
10

I haven’t used mine yet. HLG Blackbird. I have read a lot of grows on this LED and 70% seems to be the sweet spot. I have been growing outdoors for the last couple years and haven’t done an indoor since 2008 600 watt digi HPS cooltube. I’m guessing each LED and specs are going to be different. I am curious of the controls that allow you to start dim and brighten throughout the day and then dim towards the end of the 12.

2 Likes
11

I have a 4x4 with 4 HLG RSpec boards on a 600 watt driver and I can’t push these 4 boards past 450w without getting praying and other stress responses from the plants.

5 Likes
12

I run my hlg blackbird at 60% for the first 2 weeks into flower than I blast them at 100% for the rest of the grow.

6 Likes
13

That’s legit LED there. Top Notch!! If I ever get another LED in the near future it will be the RSpec for the fact you can get it closer to the canopy. :100:

4 Likes
14

I actually just got this instead as it’ll have much better spread, CRI, and far red. Should get it by next Monday so just in time for the next flower run ^^
https://www.growlightscience.com/progrow-640

5 Likes
15

You are correct , great lights great choice , spectrum is excellent .

So I read all above ….60 percent 70 percent , ligjt way up light on their heads .

Just don’t get it. Spend that kinda money on leds won’t get a par meter .:see_no_evil::see_no_evil::see_no_evil:

You set height and level BY PAR , the only thing that matters .

Great set at 70 percent . At what height , lol . Bit different at 12 inches or 3 feet .

I push as much light as I can EVERY STAGE ,.
Been doing it so long I know what PAR LEVELS I WANT AND WHEN, so I just set the lights with a par meter and I’m done .

Don’t have a meter , crank lights till you see the pray starting , then you back off till leafs drop . Praying is not a sign of health but rather too much light . Use it to set your lights if you have no meter .

Not a better deal in the market than that light for 420 bucks @HolyAngel , your gonna rock with it

Also will NEVER understand the 90 percent of growers who place the led top of tent and crank it ??? WTF ???, Use the leds no heat to your ADVANTAGE . Light at less than 20 inches , power adjusted to proper levels .

Run my veg plants at 20 percent power light 10 inches off their heads .

For reference these are what I set to

Seedlings 350 PAR
VEG 400 to 700 based on size of plants

Flower … early flower 750 to 800 . When stretch is over 900 . From mid flower to when they slow, minimum of 950 to 1000 par .
Ladies in my Tent 1 right now at start of week 7 are eating 1090 par across the canopy .

Of course , as always :sunglasses:, JMHO

9 Likes
16

Thank you. :+1:

2 Likes
17

Watch your too 2 sets of top leafs . Crank light till you see those stand up . Will take a few hours .

Reduce power till you see leaf come down and stay parallel to the floor . Won’t take much . Here in my tents it’s about 75 to 100 par difference . So at 800 they pray @ 700 leafs are down

3 Likes
18

Great subject.
Led only though :frowning:

1 Like
19

Getting a halfway decent LUX meter is one of the best gear buys I’ve made. The conversion to ppfd will get you pretty close and you have hard numbers to relate to the plants light response. Once you figure out what DLI they want you can just dial it in for each stage in the future. Mine was only like 45 bucks and it was money well spent. Without a lux or quantum meter you’re always going to be guessing.

5 Likes
20

The 600 rspec’s I have are recommended at 24-30” above the canopy. I kind of wish I’d have got a Fluence SPYDR due to the design they can be slammed right down to the canopy. The HLG blackbird may be similar.

2 Likes