Moving plants from vented to sealed room STRESS!

Hi Guys, this is my first post on here so go easy on me I have been growing for a few years and would like the say I’m fairly experienced. I have recently gone from vented grow rooms ( intake and exhaust) to a sealed grow room setup with AC, dehum, and Bottled c02 supplement.

I have been vegging my plants for 4 weeks in a vented room with everything going perfect. I have moved them into my new sealed room with temps of 28c, humidity 65-75%, and c02 @1100-1500ppm.

Here’s where the problems start.

Within 24hours of moving my perfectly healthy plants they have all starting drooping with leaves curling in. Tops of plants (flower sites) have started to turn to a very light green colour and they appear to have stopped drinking. I am very worried that my plants may start to die as they do not seem to be recovering. I have raised the lights and dimmed them down and also turned off a couple of oscillating fans to try and reduce any stress.

If anyone has experienced similar issues and could help me out. Would be greatly appreciated. Hope to hear from someone soon.

(Photos coming soon)

Thanks

What was the temp/humidity of the vented room? My initial thought is that the VPD in the sealed room is so much different than that of the vented room, causing the plants to stress and close up stomata.

"If VPD is too small, peak growth rates are not achieved, and problems like mold or root rot can become an issue. If VPD is too large, the plant stomata will close in an attempt to limit transpiration, which can result in issues like tip burn and leaf curl. VPD can be directly calculated from the temperature and relative humidity (RH) of both the plant and the grow room. Both of these concepts are explained in detail below. The surface temperature of the plant and the dry bulb temperature of the room are approximately the same, but since the plant has water forming, the plant surface will be at 100% RH when it is transpiring. For a given design temperature, we can modulate the VPD by changing the RH of the grow room.

A VPD range of 0.8–1.1 (kPa) is commonly known as ideal in the vegetative stage, while a VPD range of 1.0–1.5 (kPa) is commonly known as ideal in the flowering stage. Tables I and II show that the same ideal VPD range can be obtained at different temperatures and relative humidities.

To put it simply: Consistent temperature and relative humidity in the space*-->*consistent vapor pressure deficit --> plant transpiration --> plant growth."

Now, you might have a proper vpd in your sealed room, but if it's drastically different than what the plants have been used to, I would expect that to be the cause of the issues.

I would expect them to come around on their own, just keep an eye for major problems or problems getting worse. .if that's the case I would almost try to ease them into the new environment.

I had this happen when trying to run a Co2 generator (propane) in a smaller sealed room. Was hoping that would be the answer for you, but I re-read your post and see that you are indeed using bottled Co2.

My next thought would be something else in the room off gassing. Has this room had plants in it before? Any construction materials out of the ordinary used when building it?

What kind of lighting are they coming from and going into?

For kicks and giggles, turn the Co2 off and let them have some fresh air for a day or two and see what happens.

I had issues when I switched to sealed 9 years ago. Can’t remember the details now, but I never got to the bottom of it. Next run when the plants were raised in the sealed room everything was fine!

I know that off gassing can be an issue in sealed rooms sometimes, did you paint anything? Use silicone? Just trying to give you ideas.

It sounds to me like you put them in the room, with elevated co2, temps and light intensity, when you do this it causes the plants metabolism to speed up. The light color growth is normal for fast growing plants under these conditions.

What happens is the plants grow new tissue so fast it doesn't get its pigment quick enough and looks like its yellowing when in reality its just fresh growth and hasn't gotten its full pigment.

The leafs probably look down early in the lights on cycle after their first day cycle under co2 enriched environment during lights off its common for them to be droopy. They should recover by the end of the lights on cycle. They do tend to rest during lights off when everything else is optimal. I'm guessing your just not used to either of those and it's got you thinking something is wrong and it's probably just fine.

I'd give it a little time before getting paranoid and starting to make any changes because you could be jumping the gun and just not familiar with the growth patterns in an optimal environment.

Here is an example of the plants asleep during lights out, They stand tall and strong after an hr of lights on. This is pretty typical pattern I've experienced when I achieve optimal growth rates with co2 enrichment.





The same plants during lights on just a reference for how they look when they are really resting.

Hi guys much appreciated for the quick responses.

After dimming/raising lights and turning the c02 off I have noticed a change in the last 12 hours they are definitely perking back up. I’m agreeing with you guys that they have been shocked by change in environment. I moved 1 plant back into the vented room last night and she is almost fully recovered within 12 hours. Am going to set up an intake/exhaust and try and recreate my old environment and ease them into the sealed room. All materials in the room are new unluding plywood, adhesive spray and expanding foam both of which could be off gassing something.

Thanks again guys. Will keep you posted if there is any change

Ell94 said:

Hi guys much appreciated for the quick responses.

After dimming/raising lights and turning the c02 off I have noticed a change in the last 12 hours they are definitely perking back up. I’m agreeing with you guys that they have been shocked by change in environment. I moved 1 plant back into the vented room last night and she is almost fully recovered within 12 hours. Am going to set up an intake/exhaust and try and recreate my old environment and ease them into the sealed room. All materials in the room are new unluding plywood, adhesive spray and expanding foam both of which could be off gassing something.

Thanks again guys. Will keep you posted if there is any change

Click to expand...

Yeah sounds like you got a good general idea of other things that could be causing issues. Good luck with the grow!

I think blazeoneup nailed it. Your next run will be optimum. Remember slightly higher temps to take advantage of the extra co2, and they will use more water and nutrients. Will be epic once dialed!