how much light do seedlings need? (watts)

ma0ma0ma0

ma0ma0ma0

Member
i am germinating 12 seeds in soil. i only pan on keeping half after picking out the best seedlings. how many watts do i need to grow these seedlings indoors for the next 2-3 weeks? i have a 26 watt and 20 watts cfl that i am using, but i plan on adding more. how many watts total do you think i will need? i am also going to put the seedlings outdoors on sunny days. thanks
 
mystifiedbongs

mystifiedbongs

Well-Known Member
for 12 seedling you wont need much. i had 4- 40w 6500k, and 2- 40w 2700k cfls and under 24/0 for about a week, my seedlings flourished. you definately want more 6500k than 2700k or your seedlings will stretch.

24/0 worked great for me
 
jawbrodt

jawbrodt

Well-Known Member
Well, that all depends on how much area you want to cover. You're best bet, would be to go spend $20 on a regular T12 shoplight, and line up all 12 plants, right underneath it, about an inch away. That's one of the cheapest ways, to do it right. Your talking 2-3 weeks, which is going to take a handful of CFLs, if you want nice plants. Skimp, and you're going to have stretching seedlings, by the end of week 3. I'd figure on one 26 watt bulb for every 6" x 6" of area you want to cover. You could get away with less, if you were only planning on growing til they poke up out of the soil(a week), but after that, they start stretching, pretty fast, if you don't have enough light.
 
B

Byebyetrudeau!

New Member
Hi guys/ladies , do you think I could get away with a couple of 800 lumen 75 W LED's ? Would that be enough light if I left them in windowsill during daylight, and lights on them all night? Thanks for any input :)
 
Coloradogrower710

Coloradogrower710

Well-Known Member
Byebyetrudeau! said:
Hi guys/ladies , do you think I could get away with a couple of 800 lumen 75 W LED's ? Would that be enough light if I left them in windowsill during daylight, and lights on them all night? Thanks for any input :)
Click to expand...
I have 6 seedlings under a 77.5 watt they are doing pretty good gotta get the light close.
 
TeW33zy

TeW33zy

Active Member
Pt.1...See here's the problem I have. You guys jump into a field of agriculture with no prior training, understanding of agriculture, planting etc, u don't even know how a plant grows yet you want the results of fruit but u have no idea what u are doing, how plants grow and fruit, volumn of light per sqft, u talk ppfd non sense, u don't know nothing and u come and ask questions that u have no understanding of the question you are asking or answering.
 
Alter Jean

Alter Jean

Well-Known Member
TeW33zy said:
Pt.1...See here's the problem I have. You guys jump into a field of agriculture with no prior training, understanding of agriculture, planting etc, u don't even know how a plant grows yet you want the results of fruit but u have no idea what u are doing, how plants grow and fruit, volumn of light per sqft, u talk ppfd non sense, u don't know nothing and u come and ask questions that u have no understanding of the question you are asking or answering.
Click to expand...
Nice thread bump.

Who the hell is you? :lol:

*Edit... What's part 2?
 
TeW33zy

TeW33zy

Active Member
Pt.2...Seedlings, Veg or Flower it's all the same so let's go at seedlings. Since you all still hung on Watts then let's use Watts. You guys will put 5 plants (seedlings) under a 180 watt fixture and expect all them to grow wide and bushy. Then you will put 10 next time and expect them to grow wide and bushy yet they grow slow and stretchy. Look, 180 Watts will only grow 180 Watts of canopee across all plants. If u have 10 plants then ok, u put 20 plants ok then u put 26 ok. But no matter it's all the same canopee across all the seedlings which is why your plants are small and look little, that's because you have divided them.amongst more plants yet u don't know that. If I have 4 plants and they grow bushy and under the same fixture I put 10 plants how can u expect the same wide bushy plant canopee across all seedlings. No, it will divide it amongst all 10 seedlings. That's why u don't put more, u buy another light for more seedlings.
 
Brettman

Brettman

Well-Known Member
TeW33zy said:
Pt.2...Seedlings, Veg or Flower it's all the same so let's go at seedlings. Since you all still hung on Watts then let's use Watts. You guys will put 5 plants (seedlings) under a 180 watt fixture and expect all them to grow wide and bushy. Then you will put 10 next time and expect them to grow wide and bushy yet they grow slow and stretchy. Look, 180 Watts will only grow 180 Watts of canopee across all plants. If u have 10 plants then ok, u put 20 plants ok then u put 26 ok. But no matter it's all the same canopee across all the seedlings which is why your plants are small and look little, that's because you have divided them.amongst more plants yet u don't know that. If I have 4 plants and they grow bushy and under the same fixture I put 10 plants how can u expect the same wide bushy plant canopee across all seedlings. No, it will divide it amongst all 10 seedlings. That's why u don't put more, u buy another light for more seedlings.
Click to expand...
The fuck? Where did you come from.
 
TeW33zy

TeW33zy

Active Member
I am a Biosystems Engineer and I see so many people don't understand anything so I'll help you stop killing your grow. Seedlings show start with 25watts per plant for 30 days. If you have a 180 watt fixture divide it by 7 and u get 25watts. So the max is 7 plants, if u add 2 more u will be less and now ur plants will divide the canopp across all plants leaving u with slow, little weak plants that never branched out, overwatered because they never got wider than the bucket, that kills the roots and causes mag deficiencies then u think it's nutrients so you add more nutrients then you have burnt your plant with to many nutrients which came from overwatering then u think vpd and pH solves it. Fact is, ur plants never get wider than the bucket, they grow vertical with long legs, plants grow into the light, to much light hitting dirt and floor, no canopee, oversized bucket. 99% of growers fail from to much light, to many nutrients, to big a bucket, plants don't branch because you overwatered..
 
curious2garden

curious2garden

Well-Known Mod
Staff member
TeW33zy said:
I am a Biosystems Engineer and I see so many people don't understand anything so I'll help you stop killing your grow. Seedlings show start with 25watts per plant for 30 days. If you have a 180 watt fixture divide it by 7 and u get 25watts. So the max is 7 plants, if u add 2 more u will be less and now ur plants will divide the canopp across all plants leaving u with slow, little weak plants that never branched out, overwatered because they never got wider than the bucket, that kills the roots and causes mag deficiencies then u think it's nutrients so you add more nutrients then you have burnt your plant with to many nutrients which came from overwatering then u think vpd and pH solves it. Fact is, ur plants never get wider than the bucket, they grow vertical with long legs, plants grow into the light, to much light hitting dirt and floor, no canopee, oversized bucket. 99% of growers fail from to much light, to many nutrients, to big a bucket, plants don't branch because you overwatered..
Click to expand...
Seedling, and canopy, please elaborate
 
TeW33zy

TeW33zy

Active Member
curious2garden said:
Seedling, and canopy, please elaborate
Click to expand...
Sure. So if you want to have a wide bushy plant that always gets wider than the bucket ( which 99% of growers never achieve) then u have to look at your grow from a canopee stand point because that is what turns light into usable flower (buds/yield. 99% of growers fail because they have to many plants under a fixture. When you have to many plants, that doesn't allow the plants to branch, they then grow vertical and never branch out, then they will always be in a bucket that's wider than the canopee, that will lead to overwatering which why plants never branch out and u get these spears on the apical growth that runs into the light, that takes 70% of your yield. Therfore if u missed 70% of your yield then by definition u had to much light, to much soil, veg was 40-90 days longer than it should of been because u vegged longer to get plants to branch out but they never did so u flowered, to many nutrients etc. 70% less yield came from 70% less canopee. This is why so many people have mag deficiencies in they garden with purple stems and they think it's not enough nutrients then they add nutrients to offset then boom they killed they plant with to many nutrients because they misdiagnosed they are missing 70-80% of their canopee.
 
curious2garden

curious2garden

Well-Known Mod
Staff member
TeW33zy said:
Sure. So if you want to have a wide bushy plant that always gets wider than the bucket ( which 99% of growers never achieve) then u have to look at your grow from a canopee stand point because that is what turns light into usable flower (buds/yield. 99% of growers fail because they have to many plants under a fixture. When you have to many plants, that doesn't allow the plants to branch, they then grow vertical and never branch out, then they will always be in a bucket that's wider than the canopee, that will lead to overwatering which why plants never branch out and u get these spears on the apical growth that runs into the light, that takes 70% of your yield. Therfore if u missed 70% of your yield then by definition u had to much light, to much soil, veg was 40-90 days longer than it should of been because u vegged longer to get plants to branch out but they never did so u flowered, to many nutrients etc. 70% less yield came from 70% less canopee. This is why so many people have mag deficiencies in they garden with purple stems and they think it's not enough nutrients then they add nutrients to offset then boom they killed they plant with to many nutrients because they misdiagnosed they are missing 70-80% of their canopee.
Click to expand...
I asked you about seedlings and canopy constraints under light. Could you please focus on that.

Nota Bene: Please add white space to your walls of text, thank you.
 
You must log in or register to reply here.
Top