Seedlings - How much light and when? Too many different answers.

[justugh]

12-13 days

2ft 8bulb t5 is depending if a HO bulb or no u are still looking at only about 18k lux HO bulb 30k

honestly back the light off the plants to about 8 inches and check it daily .......think about a small fan to blow across them to remove IR heat .....just watch the speed to avoid wind burn

as for cob lights i personally think they are a joke .......for a cheap all purpose light look at apollo's
https://www.amazon.com/dp/B00FGFZ8GU/

they were a goo all around light for me .......but i grow auto flower ......but the apollo had the best mix of red and blue when i replaced them with a better LED i still kept them in the system as side lights not going to lie got me 2 oz more per plant

 

[3rd Monkey]

12-13 days

Popped on the 5th, that pic is from the 15th. 9-10 days. They're in hempy solos.

 

[Hadez411]

2ft 8bulb t5 is depending if a HO bulb or no u are still looking at only about 18k lux HO bulb 30k

honestly back the light off the plants to about 8 inches and check it daily .......think about a small fan to blow across them to remove IR heat .....just watch the speed to avoid wind burn

as for cob lights i personally think they are a joke .......for a cheap all purpose light look at apollo's
https://www.amazon.com/dp/B00FGFZ8GU/

they were a goo all around light for me .......but i grow auto flower ......but the apollo had the best mix of red and blue when i replaced them with a better LED i still kept them in the system as side lights not going to lie got me 2 oz more per plant

Meh, that Apollo looks cheap. It's 1$/w but has no listed lm/W and is primarily a blurple light.
I intend to make a range of LED products, the lowest and cheapest will be like that Apollo, for less than a dollar a watt.

 

[ANC]

My final answer is 23W spiral CFL for the first 5 days one inch away, right from the late seed stage. Thereafter you should be able to put them into your normal lighting without stretch. I find much better root development if I can delay that first stretch.

 

[justugh]

Meh, that Apollo looks cheap. It's 1$/w but has no listed lm/W and is primarily a blurple light.
I intend to make a range of LED products, the lowest and cheapest will be like that Apollo, for less than a dollar a watt.

i can personally say they work and will make the money back for u off 2 grows or less

if u want to spend
https://platinumgrowlights.com/
the p1200 i have it paid for itself in 1 grow ......but again i was auto flowers

 

[justugh]

My final answer is 23W spiral CFL for the first 5 days one inch away, right from the late seed stage. Thereafter you should be able to put them into your normal lighting without stretch. I find much better root development if I can delay that first stretch.

your insane and coming from me that is a bad thing

1 inch away the heat off it is huge ........have u ever laser temp a cfl 165f ........and the light is only effective 15 inches
u do much better with a LED 15w 6500k .....that light is effective for more then 24 inches and with 10 bulbs u will have 16k in lumens should made atleast 2 oz a plant

 

[Actuosity]

Would love to see some evidence on this. With the reflector on my tent has a lower ambient temperature above the reflector. Also without the reflector my tomatoe plates shy away from the bulbs themselves (meaning its getting stronger light from the reflection around the tent) where as with the reflector they approach the bulbs just like they do to the sun in a window. Also the top of the reflector is vented its a series of foil roll rubes cut into half to for tunnels which from my tent fan air passes through and extracts heat away from the reflector itself.

 

[3rd Monkey]

2ft 8bulb t5 is depending if a HO bulb or no u are still looking at only about 18k lux HO bulb 30k

honestly back the light off the plants to about 8 inches and check it daily .......think about a small fan to blow across them to remove IR heat .....just watch the speed to avoid wind burn

as for cob lights i personally think they are a joke .......for a cheap all purpose light look at apollo's
https://www.amazon.com/dp/B00FGFZ8GU/

they were a goo all around light for me .......but i grow auto flower ......but the apollo had the best mix of red and blue when i replaced them with a better LED i still kept them in the system as side lights not going to lie got me 2 oz more per plant

Are you saying to back my T5 off to 8"? They would stretch immensely.

Here's the node spacing with the light about 2" away.

 

[3rd Monkey]

i can personally say they work and will make the money back for u off 2 grows or less

if u want to spend
https://platinumgrowlights.com/
the p1200 i have it paid for itself in 1 grow ......but again i was auto flowers

I've always used my LED as supplemental for my HPS. I split rooms this time so the LED is on its own. So far, I'm less than impressed. Environment is very crucial to good performance with the LED it seems, and I can't always do "ideal".

The HPS on the other hand, gives no fucks. 85 degrees and 20% humidity, no problems.

The LED grows them, just not the way I like. Preference I suppose.

 

[ANC]

your insane and coming from me that is a bad thing

1 inch away the heat off it is huge ........have u ever laser temp a cfl 165f ........and the light is only effective 15 inches
u do much better with a LED 15w 6500k .....that light is effective for more then 24 inches and with 10 bulbs u will have 16k in lumens should made atleast 2 oz a plant

Try it, I have raised countless seeds with it, the heat moves up away from the bulb and plantlet. It is nothing more than cosy at an inch away., You can try it further away but you will see more stretching in front of the cotelydons. I've tried the 10W LED alternative, which although it puts out in the same ballpark lumens, the actual plantlets lacked the vigour they get under CFL. My seedlings have a small fan too.

P.S. I'm not insane, I'm emotionally disturbed.

 

[justugh]

Are you saying to back my T5 off to 8"? They would stretch immensely.

Here's the node spacing with the light about 2" away.

View attachment 4305258

not as much as u think .....keeping them that close u are heat stressing the plant ......u wantroom for the plant to grow into that way can back the light off......they will only strech if u are using 3000k veggie u should 5000k or even 6000k

 

[justugh]

Try it, I have raised countless seeds with it, the heat moves up away from the bulb and plantlet. It is nothing more than cosy at an inch away., You can try it further away but you will see more stretching in front of the cotelydons. I've tried the 10W LED alternative, which although it puts out in the same ballpark lumens, the actual plantlets lacked the vigour they get under CFL.

P.S. I'm not insane, I'm emotionally disturbed.

i have tried it .......i got to the point where i added more CFLs to the area then the AC/venting could handle
there is only one Light system i have not personally tried and that is Plasma ......i do not care how well it does super heating plasma for light in a enclosed area is dumb to me

as the plant grows if u let it grow ( mine was a 2x2 foot print about 4 feet tall) it needs new CFLs to fill the space with light ......a CFL is about 165f u can get with in about 4 inches before heat stress kicks in

 

[ANC]

 

[BostonBuds]

I just took the temp of 2 lights, the T12 6500K bulbs that have been on for days is around 95 F, a 23 watt cfl that i've had on for about 2 minutes is already at 155 F.

 

[3rd Monkey]

not as much as u think .....keeping them that close u are heat stressing the plant ......u wantroom for the plant to grow into that way can back the light off......they will only strech if u are using 3000k veggie u should 5000k or even 6000k

I've been using this light for 8 years, working on this strain for 6.

There's no light/heat stress that close. I know for a fact, if I back that light off, they will stretch. 6500k

 

[BostonBuds]

Getting warmer...

 

[3rd Monkey]

Getting warmer...
View attachment 4305269

Doesn't mean much. Put a plant under it 1-2" away and check LST. That'll tell you what you need to know.

 

[drsaltzman]

Home growers usually have different results because they have different environments/seeds/temps etc... even if they’re using the exact same equipment.

CFL works for seedlings. Has for decades.
If you stretch, adjust the height.
Then bury those puppies up to their neck when you plant up.
Done.

 

[danjac82]

Popped on the 5th, that pic is from the 15th. 9-10 days. They're in hempy solos.

Lol, w

to help take off the tin foil ........it is doing more damage then good the the foil reflects and retains the heat ( cold grows ok but anything above 60F it isbad idea)
look into something called IR blocker..........yes it does reflect heat but the patternes in it defuses the light in a useable way

to help take off the tin foil ........it is doing more damage then good the the foil reflects and retains the heat ( cold grows ok but anything above 60F it isbad idea)
look into something called IR blocker..........yes it does reflect heat but the patternes in it defuses the light in a useable way

Aluminum foil is better than nothing. There is a big difference between using just a homemade bare cardboard reflector and one that’s lined with foil. Use duller side. Used to do it all the time. Sure, not the most efficient but better than nothing and never had a hot spot.

 

[danjac82]

your insane and coming from me that is a bad thing

1 inch away the heat off it is huge ........have u ever laser temp a cfl 165f ........and the light is only effective 15 inches
u do much better with a LED 15w 6500k .....that light is effective for more then 24 inches and with 10 bulbs u will have 16k in lumens should made atleast 2 oz a plant

I keep many bulbs an inch away and no heat

T5:within 2 to 3 inches of plants is the right way to go if you know anything about T5s. I go even closer and kick my fan up to keep temps in range. No heat stress. You’re recommendation of spacing from light is going to grow some stretched wimps.