UN-Spiking Transpiration Rates: Transition from Lights On to Lights Off - Growroom Designs & Equipment - International Cannagraphic Magazine Forums

Douglas.Curtis · 01-24-2018, 01:34 AM

Has anyone monitored transpiration rate changes between lights on and lights off, with HID? What about with LED?

When temperatures and RH stay the same, what happens to transpiration rates when photosynthesis shuts down for the night? Does the plant use less water? Does the amount of water moving through the plant change? If so, how and how much?

I'm hoping someone has done extensive testing on this and has some data to share.

Anyone?

Dropped Cat · 01-24-2018, 04:21 AM

spurr had lots to say about the dump, look for his posts on the subject.

suzycremecheese too.

If I remember correctly, lol

Both these members sorely missed.

toxic hippie · 01-24-2018, 04:28 AM

I run a sealed room and I monitor conditions 24/7. What I’ve noticed is for the first 2 hours of lights off the plants are perspiring like the lights were still on. Then it slows down.

Phaeton · 01-24-2018, 05:37 AM

I run an unsealed room, three actually.
The bud room usage is as posted above. Overall the water used during the 12 hours of dark is 80% of the six hour morning usage when lights are on. Overall water usage is less with LED versus HID, but the light/dark ratio remains the same.
Short story, usage is about half as much per hour when averaged overnight.

The open veg areas do not have a sharp cutoff on light and no major reduction is noticed in water usage during the six hours of darkness versus the first six hours of light.
It is there but small enough the watering routine is not altered.

Douglas.Curtis · 01-24-2018, 06:13 AM

What are the temp/RH changes in your respective rooms, at lights out and into the dark? Appreciate the tips on other threads to look up, I'll be reading up on them for sure.

toxic hippie · 01-24-2018, 04:20 PM

Lights on 81-83 and 58-63%. Lights off 79-81 and 58-65%

01-24-2018, 01:34 AM	#1
Douglas.Curtis Senior Member Join Date: Jul 2016 Location: Back in Colorado! Yaay! Posts: 2,260	UN-Spiking Transpiration Rates: Transition from Lights On to Lights Off Has anyone monitored transpiration rate changes between lights on and lights off, with HID? What about with LED? When temperatures and RH stay the same, what happens to transpiration rates when photosynthesis shuts down for the night? Does the plant use less water? Does the amount of water moving through the plant change? If so, how and how much? I'm hoping someone has done extensive testing on this and has some data to share. Anyone? __________________ "Secrets to Growing Trichome Dense Cannabis" Now Available in Print! My intentions are noble, pay no attention to my autistic lack of diplomacy.
	Quote 1 members found this post helpful.

01-24-2018, 04:21 AM	#2
Dropped Cat Six Gummi Bears and Some Scotch Join Date: Jan 2014 Posts: 2,615	spurr had lots to say about the dump, look for his posts on the subject. suzycremecheese too. If I remember correctly, lol Both these members sorely missed. __________________ "So we're just done with phrasing, right, that's not a thing anymore?."
	Quote 1 members found this post helpful.

01-24-2018, 04:28 AM	#3
toxic hippie Member Join Date: Mar 2014 Location: earth Posts: 805	I run a sealed room and I monitor conditions 24/7. What I’ve noticed is for the first 2 hours of lights off the plants are perspiring like the lights were still on. Then it slows down.
	Quote 1 members found this post helpful.

01-24-2018, 05:37 AM	#4
Phaeton Speed of Dark Join Date: Apr 2011 Location: Interior Alaska Posts: 1,554	I run an unsealed room, three actually. The bud room usage is as posted above. Overall the water used during the 12 hours of dark is 80% of the six hour morning usage when lights are on. Overall water usage is less with LED versus HID, but the light/dark ratio remains the same. Short story, usage is about half as much per hour when averaged overnight. The open veg areas do not have a sharp cutoff on light and no major reduction is noticed in water usage during the six hours of darkness versus the first six hours of light. It is there but small enough the watering routine is not altered.
	Quote 1 members found this post helpful.

01-24-2018, 06:13 AM	#5
Douglas.Curtis Senior Member Join Date: Jul 2016 Location: Back in Colorado! Yaay! Posts: 2,260	What are the temp/RH changes in your respective rooms, at lights out and into the dark? Appreciate the tips on other threads to look up, I'll be reading up on them for sure. __________________ "Secrets to Growing Trichome Dense Cannabis" Now Available in Print! My intentions are noble, pay no attention to my autistic lack of diplomacy.
	Quote

01-24-2018, 04:20 PM	#6
toxic hippie Member Join Date: Mar 2014 Location: earth Posts: 805	Lights on 81-83 and 58-63%. Lights off 79-81 and 58-65%
	Quote 1 members found this post helpful.