Clone / Seedling Light Transition Stress from T5 to LED PPFD PFD PAR

jaked3800

Active Member
I had some clones planted in peat/coco in 750ml pots under T5 at about 230 ppfd pfd. Transplanted them to 5 gallon buckets and moved them to the flower room where I have HLG scorpion diablo 650 LEDs. I bumped the light to around 250 ppfd and was going to slowly increas to 350-400 to veg them out. I noticed some of the plants showed stress after about 16 hours (I do 24/0 light for veg). So I backed the ppfd down to 130-140 at the max light points. They seemed to bounce back a bit already and its only been about 10 hours since the change.

So is it that the light from the LED is so efficient and the plant uses so much of the spectrum that I should actually be lowering my ppfd a bit initialy to transition them or is there something else going on here. I kept temp and humidity about the same as it was under the T5s
65% humidity 75 degrees F and will taper the humidity down in the coming weeks and temperature up.

But I was on the lookout for transition stress as this happend on my last round aswell and it just slowed my veg time down from having to recover from whatever stress they were experiencing. Mostly yellowing top leaves curling down big time in some of the plants.

So my main thought/ question is should I optimally be dialing my ppfd down a tad coming into the LEDs from the ppfd that I was at on T5's?
Any input appreciated.
 
Last edited:

bubblescrogs

Well-Known Member
I had some clones planted in peat/coco in 750ml pots under T5 at about 230 ppfd pfd. Transplanted them to 5 gallon buckets and moved them to the flower room where I have HLG scorpion diablo 650 LEDs. I bumped the light to around 250 ppfd and was going to slowly increas to 350-400 to veg them out. I noteced some of the plants showed stress after about 16 hours (I do 24/0 light for veg). So I backed the ppfd down to 130-140 at the max light points. They seemed to bounce back a bit already and its only been about 10 hours since the change.

So is it that the light from the LED is so efficient and the plant uses so much of the spectrum that I should actually be lowering my ppfd a bit initialy to transition them or is their something else going on here. I kept temp and humidity about the same as it was under the T5s
65% humidity 75 degrees F and will taper the humidity down in the coming weeks and temperature up.

But I was on the lookout for transition stress as this happend on my last round aswell and it just slowed my veg time down from having to recover from whatever stress they were experiencing. Mostly yellowing top leaves curling down big time in some of the plants.

So my main thought/ question is should I optimally be dialing my ppfd down a tad coming into the LEDs from the ppfd that I was at on T5's?
Any input appreciated.
They always throw a bit of a hissy if I move them straight from the T5 to LED. Found moving them under the LED for a couple of extra hours each day keeps them happier
 

jaked3800

Active Member
They always throw a bit of a hissy if I move them straight from the T5 to LED. Found moving them under the LED for a couple of extra hours each day keeps them happier
Interesting, I have done the transition smoothly in the past but I never really kept detailed numbers of what the light intensity was/ how far my lights were before I recently got my light meter. But maybe ill introduce a LED to my veg/clone room for a few hours before next time I do this.
 

jaked3800

Active Member
Work out your DLI because you are running 24/0

Get your temps up as soon as they go under LED.
Yeah even with 24hrs with DLI taken into acount I should be at atleast 250 ppfd. Im going to slowly increase to that aswell as temperatures.
Any input on how quickly I should increase the ppfd? Im thinking 30-40 per day as I typicaly veg in the 5 gallons only 7-11 days before the flip to 12/12
 
Top