Answered How much and how close? LED/Seedlings

jpcyan2

In Bloom
Having never used LED's to start seedlings, I'm unsure how much wattage and what distance is suggested for the first few weeks?

I'm using Daylight spectrum 5000k, 60W equivalent, medium base, standard replacement bulbs with the plastic domes removed. Rated at 800 lumens each.
Currently have 2 bulbs about 12" inches above the starter tray. I can run as many as 6 bulbs with the fixtures and space available.
The tray is 1/3 smaller than a standard seedling flat.
I know there will be a learning curve switching from CFL to LED and appreciate all the info and advice I've already gathered from y'all.

So.. How many bulbs and what distance would you use?

1- 42220.jpg
 

JL2G

πŸ…±οΈπŸ†’οΈπŸšΉ
Staff member
Q-36 Space Modulator
I have 5 of them in a row in my 1'x3' seed starter box. Three 5000k, and two 3000k ones 60w each, no domes on them either.
For seedlings I have them about 10"-12" off the tops of the soil.
As they pop and get bigger i let them keep going up and to about 4" away before I start moving it up. I have them attached to that shelf.
20191203_184741.jpg
They can actually be within an inch or two with not burning in my experience.
I move them up for better light spread at four inches distance though.

I've done large arrays as well.
This was used in my veg room but it's been flowered under as well.
See how close they can get to a full blown plant. Almost touching before any burn.
20191012_065756.jpg
My growmie is using it now since I upgraded last year for my veg room. Gave him the bro deal of free. Lol.
 

NotAquaMan

In Bloom
Download "light meter" by "my mobile tools dev" it's a lux meter. It's not the best meter as it's simply an app and lux is not the best measurement to use but it will get ya dam close to the ideal intensity as long as your not using blurples since some of that light falls outside the spectrum measured.

Seedlings about 5k, slowly increased every few days by about 3-5k increments.

Early veg 20kish

Late veg 40kish

50-75k flower
 

JL2G

πŸ…±οΈπŸ†’οΈπŸšΉ
Staff member
Q-36 Space Modulator
Do you use these transitioning from
T-5 to LED grow lights or do you start seedlings under the led bulbs?
Wasn't sure if you were asking me but I'll answer anyways. Lol. πŸ˜πŸ˜πŸ˜‰
I've been led from the get go. No t 5 ever.
The small box was my seed starter, and or clone box from when I only had one room.
Used pretty much constant. Lol.
Does an amazing job for super dirt cheap.
The small box was about $20 in materials to make. 5 bulbs, 50 real watts.
The big light array was about $100. 40 bulbs, about 400 real watts.
 

spyralout

🌱🌿🌲πŸ”₯πŸ’¨
Staff member
No different then MH vs HPS. Spectrum actually has more to do with plant structure. Intensity is the amount of photons and that's what the plants use photo synthesize of course there are different receptors for different spectrums and red and blue being the most efficient but contrary to old school thinking green plays a decent roll as does UV and IR
I have noticed the green at sites like Rapid LED, but not in puck form. I have the makings for Emerson and UV, but not sure how to run them yet. Like if I had the different spectrums on timers or a controller, to turn on/off certain light at certain times of the day. I know of the far red initiator 15min after lights off, going to try all of this too this run. I just don't want to overdo one spectrum or another because I had some clones under some super cheap chinese blurples that weren't blue at all, just blinding red. Those plants were really gangly/spindly weird and I ended up culling them because they seemed to be really susceptible to just about anything.
 

Jewels

Tilts at Tables
I am going to have to "arrow up"Jesse's reply on this one. He is the one that taught me the domeless LED trick, I couldn't comment on this post without mentioning that.

On a baby, using those 13watter's, I would see stress when closer than 10 inches.
 

JL2G

πŸ…±οΈπŸ†’οΈπŸšΉ
Staff member
Q-36 Space Modulator
I have noticed the green at sites like Rapid LED, but not in puck form. I have the makings for Emerson and UV, but not sure how to run them yet. Like if I had the different spectrums on timers or a controller, to turn on/off certain light at certain times of the day. I know of the far red initiator 15min after lights off, going to try all of this too this run. I just don't want to overdo one spectrum or another because I had some clones under some super cheap chinese blurples that weren't blue at all, just blinding red. Those plants were really gangly/spindly weird and I ended up culling them because they seemed to be really susceptible to just about anything.

All spectrums except UV (unless super low intensity which is not usual) are good to run the full light cycle. IR needs to be balanced as to much will cause leaf temps to rise possibly to high. Then it would need cycled
Agreed.
I like this guy, he breaks things down really well with real data.
Dr Bruce Bugbee, he has alot of really good videos on you tube all about spectrums.
 

Deebs

The Sentient Naturewalker
Staff member
Moderator
Download "light meter" by "my mobile tools dev" it's a lux meter. It's not the best meter as it's simply an app and lux is not the best measurement to use but it will get ya dam close to the ideal intensity as long as your not using blurples since some of that light falls outside the spectrum measured.

Seedlings about 5k, slowly increased every few days by about 3-5k increments.

Early veg 20kish

Late veg 40kish

50-75k flower
Awesome man! I have been wanting to grab something like this. Thx~
 

jpcyan2

In Bloom
Heh, I don't own a smartphone.. I do have an el cheapo light meter that I have figured out pretty well by years of testing CFL in various position, fixtures and hood setups. I know what works and what the readings should indicate with those. Maybe I can use that as a baseline.

The tent is just shy of 3x3 and 5ft tall. Normally the top is used for clones in a bubbler and the bottom for Mothers. Sometimes for vegging.
The lower part of tent uses an 8 bulb, 2ft T-5, which is down to 2 working bulbs.
Looking forward to replacing that with a real LED board ;)πŸ‘Š:D
The flower room has a 4x4 and a 2x4 tray with a 1K Super ES HPS on a rail/mover.
Replacing that with an LED seems like it might be pretty expensive up front. I want some experience and test time in on the LED's before I go there.

Good stuff and answers, thanks!
 

NotAquaMan

In Bloom
I have 5 of them in a row in my 1'x3' seed starter box. Three 5000k, and two 3000k ones 60w each, no domes on them either.
For seedlings I have them about 10"-12" off the tops of the soil.
As they pop and get bigger i let them keep going up and to about 4" away before I start moving it up. I have them attached to that shelf.
View attachment 8320
They can actually be within an inch or two with not burning in my experience.
I move them up for better light spread at four inches distance though.

I've done large arrays as well.
This was used in my veg room but it's been flowered under as well.
See how close they can get to a full blown plant. Almost touching before any burn.
View attachment 8321
My growmie is using it now since I upgraded last year for my veg room. Gave him the bro deal of free. Lol.
Beautiful 😍
 

spyralout

🌱🌿🌲πŸ”₯πŸ’¨
Staff member
I have 5 of them in a row in my 1'x3' seed starter box. Three 5000k, and two 3000k ones 60w each, no domes on them either.
For seedlings I have them about 10"-12" off the tops of the soil.
As they pop and get bigger i let them keep going up and to about 4" away before I start moving it up. I have them attached to that shelf.
View attachment 8320
They can actually be within an inch or two with not burning in my experience.
I move them up for better light spread at four inches distance though.

I've done large arrays as well.
This was used in my veg room but it's been flowered under as well.
See how close they can get to a full blown plant. Almost touching before any burn.
View attachment 8321
My growmie is using it now since I upgraded last year for my veg room. Gave him the bro deal of free. Lol.
OG Kitchen Sink light. Where's Mr. Nicholson? Maybe a cameo appearance one day.
 

JL2G

πŸ…±οΈπŸ†’οΈπŸšΉ
Staff member
Q-36 Space Modulator
I never noticed the bedazzled part LMAOOOOOOOOπŸ˜‚πŸ˜‚πŸ˜‚
It's a picture of a painting on the wall at one of the local restaurants I used to frequent before covid shit happened.
Jack is a bad ass actor, one of my favorites from the days. That painting too just has his look.
To me it says, " I'm a bad ass, even with bed head and bedazzled. You think I give a fuck? " Lmfao.
 

spyralout

🌱🌿🌲πŸ”₯πŸ’¨
Staff member
The spectrum/intensity thing sounds like an "it'll get the job done" vs "precision crafted" type of deal. Like if you had a tiny tack, and you whacked it with a sledgehammer, it would get the job done all smashed up n terrible looking, but with a smaller ball peen hammer it drives it in more precisely.
 

NotAquaMan

In Bloom
The spectrum/intensity thing sounds like an "it'll get the job done" vs "precision crafted" type of deal. Like if you had a tiny tack, and you whacked it with a sledgehammer, it would get the job done all smashed up n terrible looking, but with a smaller ball peen hammer it drives it in more precisely.
No different then MH vs HPS. Spectrum actually has more to do with plant structure. Intensity is the amount of photons and that's what the plants use photo synthesize of course there are different receptors for different spectrums and red and blue being the most efficient but contrary to old school thinking green plays a decent roll as does UV and IR
 
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