UN-Spiking Transpiration Rates: Transition from Lights On to Lights Off

Douglas.Curtis

Autistic Diplomat in Training

• Jan 24, 2018

• #1

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

Six Gummi Bears and Some Scotch

Veteran

• Jan 24, 2018

• #2

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

Member

• Jan 24, 2018

• #3

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

Speed of Dark

Veteran

• Jan 24, 2018

• #4

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

Autistic Diplomat in Training

• Jan 24, 2018

• #5

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

Member

• Jan 24, 2018

• #6

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