PAR for seedlings

[Talonxracer]

I am starting 3 new plants in solo cups for an outdoor grow. I have used various schemes when starting seedlings with just as various and inconsistent results. Currently I have one of my half sunboards with (48) lm301h 3500k leds setup over top of the solo cups. I have one of my controllers temporarily hooked up so I can set a output from about 4umols on up to about 195umols at a height of 16".

For you guys using a PAR meter what would be a good PAR/PPFD for some new girls? I would like to give them a decent chance this go-around! LOL

 

[Talonxracer]

Here is a quick shot of the impromptu setup for the new girls to start in. I have them in the typical red solo cup and dome tops from McDonalds large milk shakes.

 

[Drownomatic]

18/6 10 DLI up it by 3-4 each week if it can take it.

if leaves droop a few hours before lights out, its too bright.

 

[Talonxracer]

Thanks!

18/6 10 DLI up it by 3-4 each week if it can take it.

I have a question about DLI (some thing that was fairly new to me until I joined the site), when you compute the DLI you take into account the actual light-on hours, so I would use 18 versus 24 when running the 18-6 lighting scheme, correct?

 

[Drownomatic]

Correct. DLI is Moles of light per meter per day.

Once you have your PPFD, you can calculate your DLI:

1. PPFD measures micromoles per second, so take your PPFD and multiply it by 60 to get micromoles per minute
2. Multiply your figure above by 60 again to get micromoles per hour (you can combine steps 1 and 2 by multiplying your PPFD by 3,600)
3. Multiply the above figure by the number of hours your lights will be on to get micromoles per “day”
4. Divide the above figure by 10^6 to convert it from micromoles per day to moles per day (using a calculator, enter 10, then press the xy button, then enter 6)

This will be your DLI.

 

[Talonxracer]

Thanks a million for verifying that for me!

Easy enough!

 

[Death The Cultivator]

For seeds and clones - 8-12 DLI
For Veg - 15-20 DLI
For Flower - 30-40 DLI

Daily Light Integral (DLI) Calculator | Waveform Lighting

With a PPFD input value and total hours of use per day, Daily Light Integral (DLI) values can be calculated using our online calculator.

www.waveformlighting.com

 

[Talonxracer]

Thank you for the numbers!

 

[automan2]

For years, I've used a simple 4 bulb, 24" 6500K T5HO to start every plant at 24/0 for 3 weeks. Keeping temps in check and keeping light at 2-3 inches has given me many many healthy seedings. Never gave dli/ppfd any thought...checked it recently...was 3-400ppfd at 18-20dli at 3 ". Has been working so good, it's the only thing I haven't upgraded in over a decade.