Bilbobudkin420
Well-Known Member
Ahhh i see. You start counting later than me thats why theres such a difference lolBig Brook
Baby Brook
Blue 1
Blue 2
Blue 1 Budding
Group
Group
Easiest Nute Program Ever: Brooklyn Sunrise & Blue Dream'matic Autos
- Thread starter farside05
- Start date
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- #162
@Bilbobudkin420 That's why I thought it best to show the representative picture of the day I used for calculation. That pic was of Blue 1 which was 1st. Blue 2 which should be a better yielder was a little behind that. Baby Brook was last since she was planted a week later, although she matured faster.
Bilbobudkin420
Well-Known Member
Ok sweet. My blue dream is going crazy man. Hope she hits flower hard soon. Shes starting to throw a few pistils here and ther but not enough to call it flowering just yet
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- #164
Just ordered a cheap ($20 USD) lux meter to try to get a better handle on this new light. Probably should have done that at the beginning of this grow. I believe I've encountered some light stress with these girls. This should help me either figure out how high to run this light or adjust the dimmer accordingly.
Info from Royal Queen Seeds website:
HOW MUCH LIGHT DO YOUR CANNABIS PLANTS REQUIRE?
Note: numbers are for "white light" like COBs, strips, QBs, HPS, or MH. It doesn't work like that for blurple LEDs.
Info from Royal Queen Seeds website:
HOW MUCH LIGHT DO YOUR CANNABIS PLANTS REQUIRE?
- Clones and seedlings: 5,000–7,000 lux
- Vegetative growth: 15,000–50,000 lux
- Flowering: 45,000–65,000 lux
- Maximum recommended amount of light: 75,000 lux
Note: numbers are for "white light" like COBs, strips, QBs, HPS, or MH. It doesn't work like that for blurple LEDs.
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- #165
Got home from work and did some calculations. We'll see what the meter says Friday. Given the projected output of my light, and the space its confined to, the estimated lux comes out to be 80,288 which exceeds the 75,000 maximum. So light stress is a good possibility. My old lighting's estimate was 26,634 in comparison.
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- #166
Day 56 & 49
EastCoastGhost
Well-Known Member
I need to get me a meter also. I would like to get a quantum meter, it measures umoles, not sure I spelled that right but I’ve been reading a little and found this
You probably know more about it than I do. Is lux and umols different? Idk which would be better, measuring lux or umols. I’m thinking the quantum meters are pretty expensive though.
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- #168
@EastCoastGhost I'm no lighting expert by any stretch. Umols, PAR, lumens, lux, they are all different units of measure with lumens and lux most closely related. Lux is lumens given a specific space. Meters that measure PAR are quite expensive (ie $500) whereas lux meters are pretty cheap ($20 on @mazon). From my limited research, for blurple LEDs you have to use par values, whereas you can get away with a lux meter for white light LEDs and standard bulb type lights. Since I'm running 3500k LEDs I thought I'd give a cheap lux meter a go. Interested to see if it's better to run the light closer at a value less than 100% or higher and at full strength. I'll check and see the amount of light drop-off at the top of the canopy vs several inches down under several heights and power levels to make that determination. I do know that 100% (or at least 100% of what my driver can push, that's about 75% of what the strips can take) and the lights current height, I'm getting some bleaching of my top Foliage.
I need to get me a meter also. I would like to get a quantum meter, it measures umoles, not sure I spelled that right but I’ve been reading a little and found this
You probably know more about it than I do. Is lux and umols different? Idk which would be better, measuring lux or umols. I’m thinking the quantum meters are pretty expensive though.
I m not an expert neither but have read a lot about it. Check the first post of my current journal for interesting links about LUX, PAR, how much is needed for weed, video review, etc.... It's really interesting!
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- #170
@flashmp3 I had read the he Grow Weed Easy article along with the Royal Queen blog that I posted the excerpt of. That's what prompted me to buy the lux meter to try to dial in my lighting better. 
. I'll have to check out the rest when I get hone from work.
. I'll have to check out the rest when I get hone from work.
@flashmp3 I had read the he Grow Weed Easy article along with the Royal Queen blog that I posted the excerpt of. That's what prompted me to buy the lux meter to try to dial in my lighting better.
Haha they may be the first articles I started with. Then I found the videos of a guy known on YouTube as growsrecrets which make different tests and comparison on led lights. I realized we can't really trust what the brands advertise and definitely need a lux or even better par meter, to put the lights at the perfect distance etc..... I also found a very interesting article about some studies on the sweat spot for PAR/temperature for best photosynthesis. There some other interesting ones as well in my first post. Check it when you have time they are worthy
@EastCoastGhost
I searched the zon for quantum meter. I bought one from hydrofarm for $130....my growshop had it for $90.
I searched the zon for quantum meter. I bought one from hydrofarm for $130....my growshop had it for $90.
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- #173
So the meter came in this morning. I can see a couple hour session gathering data and an Excel spreadsheet in my future. Trying to find the best combination of height and power isn't going to be simple, but I love data and analysis, so this should be fun. At the moment I dropped the lights down to about 6 inches from the tops and turned it down to about 80% power. A quick initial data gathering was showing if I had 60,000 at the tops with the light running full blast and about 18 inches away from tops, 4 inches down it would drop to 40,000. If I ran the light closer, about 6 inches from tops, and turned the dimmer down till I had 60,000 lux, I had less drop off 4 inches further down. I need to think about how I'm going to conduct my tests and format my data table. I have a couple days to figure that out because I won't have time to devote to it until Monday.
This post inspired me so I decided to buy a brand new battery for my lux meter. I measured the sun light outside as it s very bright today. Around 10am it was around 90000-100000 then at 1pm It was around 120000 lux. I don't know if the max is 100000 or 120000 lux as websites say both. Anyway so I decided that as Sativas and hybrid can thrive outdoor in country with tons of bright days like in California for example, I would try to give my girls a value close to what happens outdoor. I decided to lower my lights so that my lux meter shows around 100000 lux. This allow me to remain a bit lower than outdoor at peak. Some of my girls were still stretching at week 7 and I think they wouldn't if the lights have been lower. I ll see how it goes in the upcoming days!
EastCoastGhost
Well-Known Member
That would definitely be fun to play with and ultimately dial your lighting in. I’m gonna have to get a meter and play with my setup lol.
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- #176
I'd be cautious at that intensity. Both articles don't suggest going over 85000 and you can see stress over 75000. They recommend more like 65000. Grow Weeds article says autoflowers can take less and I've experienced that. One of my autos was showing stress at less than 65000, so it can be plant specific. The sun can be 100000, but its not that intensity all day long. Some of the DIY guys get so anal that they buy controllers that allow them to vary the light intensity over a day to mimic the sun traveling across the sky. Keep a close eye on them for any discoloration of the top foliage.
From Grow Weed Easy
How much lux do you want to deliver to your plants?
Quick Guide – Lux Levels for Optimal Cannabis Growth
Life StageMaximumGoodMinimumVegetative70,000 lux40,000 lux15,000 luxFlowering85,000 lux60,000 lux35,000 lux
< 15,000 lux – sparse or “stretchy” growth – plant isn’t getting enough light
15,000 – 50,000 lux – good amount of light for healthy vegetative growth
45,000 – 70,000 lux – optimal amount of light for cannabis plants in the flowering (budding) stage
70,000 – 85,000 lux – a lot of light, some strains thrive at this light level, but some plants (especially auto-flowering and indica strains) lose their top leaves early under this light intensity and need lights to be kept further away for healthy growth
> 85,000 lux – at this light intensity, you’ve hit the plant’s “saturation point” which means your plant can’t use all the light (be careful of light bleaching!)
What Happens If I Give My Plants Too Much Light?
The amount of light you get from direct sunlight on a bright, sunny day is 40,000 up to about 100,000 lux. At the high end there’s more light than the plant can use. Imagine a cannabis plant in a pot in the desert – the direct sunlight would be too much.
When growing cannabis, you don’t really get any additional gains by adding more light to get over 85,000 lux. Not only is it the extra light wasted by your plants, too much light can actually give your plants unsightly light burn or cause it to lose its leaves early!
From Royal Queen
HOW MUCH LIGHT DO YOUR CANNABIS PLANTS REQUIRE?
- Clones and seedlings: 5,000–7,000 lux
- Vegetative growth: 15,000–50,000 lux
- Flowering: 45,000–65,000 lux
- Maximum recommended amount of light: 75,000 lux
What about even more light? At some point, increasing the light beyond a threshold plant can manage will actually diminish returns. Said differently, once you reach about 85,000 lux, it’s simply too much. Some strains may already show signs of light stress at only 75,000 lux, with the risk of light bleaching increasing at over 80,000 lux. To keep it safe, it is best to stay at or below 75,000 lux.
EastCoastGhost
Well-Known Member
Good info there farside. I’ve been keeping my light at 22-24in, Penny has a quantum meter and we have same boards so I’m going off his measurements since I don’t have a meter yet. He said penetration and all is better at 24in with the 288 boards. I think his has the 561c diodes but I’m not sure. Mine has the newest 301B diodes so that may make a difference but idk. One day I will get a meter so I can play around with it.
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- #178
@EastCoastGhost whatever you are doing they seem to enjoy. Your plants all look amazing.
This is what the light stress on Blue 1 looks like. The rest of the plant looks fine, it's just the very top leaves. It happened when she was the biggest plant and was closer to the light than her sisters. It kinda stopped her in her tracks.
This is what the light stress on Blue 1 looks like. The rest of the plant looks fine, it's just the very top leaves. It happened when she was the biggest plant and was closer to the light than her sisters. It kinda stopped her in her tracks.
Thanks for reminding that. You re so right about the light intensity not being equal and maxed out all day long. I ve done different tests in the past and it went pretty well at the condition the lux meter to read good values. My goal is to provide the maximum amount to lower bud sites. In nature whenever they get hit by light it s same lux whatever around tops of bottom. Unfortunately it doesn't happen inside. So I think the most important is not too go over sunlight max lumens. Cause again, in nature, Sativas thrive under long sunny days outdoor without light burn. So at the end, I m convince that the plant will still receive less overall light than if it was outdoor in a country with friendly climate. I did no science lol just my two cent but for the moment it works well without burn. Only time one plant I had was burnt was if I had gone out of the house a few days and not adjusting light level while plants are growing, or if my lux meter wasn't reading accurate values because of bad battery
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- #180
Took the saucer and riser out from under the tallest plant and stacked it under the shortest plant to help level the canopy. Probably should have done that a long time ago. Not sure why it didn't really cross my mind. Maybe it's because I'm used to having a dedicated light for each plant that I would run at different heights rather than one big lamp for the tent. Adjusted the light height so that the tallest cola is getting 65,000 lux and the rest of canopy is around 50,000. Will give that a try.
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