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Experienced Sealed Room Growers needed

Good day. So this potential issue has been going on for over a year. Let me give you some background on the grow space. I apologize if this is hard to read or understand. Trying to put a years worth of thoughts into this.

My grow space in the beginning was a passive grow area utilizing negative pressure with no co2 enrichment. I was consistently producing 1.25-1.5lbs per light with this setup. Plants were healthy and everything was good but then i wanted to be even better. I felt that using outside air to cool my room was leaving some yield out there as i couldn't control all aspects of the environment perfectly as well as worrying about bringing in potential problems from outsude. So i took a big leap and invested a lot of money and time to try and create the best environment i could for my ladies.

Out with the intake, see ya later exhaust. I invested in a 4 ton ac to control the temps of my 8 1000 watt non air cooled lights. I invested in a Quest industrial grade dehumidifier to make sure when the ac was satisfied that the humidity wouldn't rise. For co2 enrichment i chose to use a natural gas burner that I tied into my houses supply so i never had to deal with tanks,etc. The ac can handle the extra heat load from it and the dehu easily cleared the excess humidity it created. I also installed a uv light inside the air handler of the ac that was supposed to keep mold and viruses from growing(not a ozone generator). Just a preventive measure.

Before i dive into the symptoms that i am experiencing let me tell you that i have plenty of growing knowledge and have gone over every single aspect that could of potential bad horticulture practice. I have covered all my bases on that end which leaves me no doubt that it is something environmental. This is why i am leaving out all the small details(ph, lamp height,etc.) If we think they are necessary i can add them on here.

Over the last year i have been averaging 1lb per light and have seen a decrease in my yields from my previous grow space design. not what i was hoping for!

The plants are healthy, drink and feed normally. But the once thing they lack that i was used to seeing before is stem girth and hardiness. Not the stalks, but the stems leading to the buds. Typically in the amount of veg time they are getting the stems should be very strong and thick and ready to host a monster cola.

My gutt instinct has been telling me that i need to exchange the old air in the grow space periodically throughout the 24hrs. But according to the theory of completely sealed grow spaces this should not be necessary. Plants should be producing the needed o2 for the root zone and no need to exchange the air.

These are the signs im getting thats telling me something is wrong:

1) Even though the temps and humidity are where they should be, it still feels and smells somewhat stale and musky in the room. If temps and humidity are right and still feels bad that means anaerobic air right? But how?

2) am seeing an abnormal about of mushrooms growing out of the soil(soil is not logged and dries out normally)

3) Stems are softer and smaller diamater then i am used to seeing for veg time. 3 weeks after the last top the stems are about pencil size, before the sealed room they were like sharpie size.

4) Typically after super cropping and bending my plants i would see HUGE knots from where the damage was within a week or so. But since the room was sealed the knots would form but were very small fraction of the size i typically get.

5) aerobic smells inside my house. Used to smell like straight chron inside my house. now i get a musky not so good smell at about 4 weeks into flower.

6) The quality of the bud after harvest lacks luster and typical Trichome production. Its still good, just not the super funk it was before.

So my final thoughts on what i think might be the problems and what i have currently done to try and resolve.

1. The room would hold the co2 at around 800-1000 through the night period. I have read some info saying that is bad but the source was not credible and couldn't find any more info on that.

2. Somehow the plants are not producing enough oxygen to keep up with demand without replenishing the air? Possibly the burning flame from the co2 burner is eating up plants oxygen?

3. Are co2 generators(burners) not suitable for sealed grow spaces? I know its burning the correct colored flames and my carbon monoxide alarm has never been alarmed. Again no info online about using burners in sealed rooms.

So last night i went ahead and broke the seal on the room and re installed my exhaust system to come on for one minute off for 4 minutes. Within no time my whole house felt and smelled better. When you walk into the grow it now feels much crisper.

My plan is to also re install the intake so that periodically i am exchanging filtered outside air into the space. But this totally contradicts the sealed grow space techniques.

I manage a 60 light medical grow here in Denver and we grow in sealed rooms with bottled co2, much higher ceilings, and roof mounted air conditioners. Same basic growing methods but different spaces. Works just fine there. Weird

I have gone INSANE trying to dial this room in. Was i completely missing something important when entering the sealed grow space realm? Anybody ever experienced anything similar?

You guys are awesome, feel free to ask any questions or if you think pics are helpful i can add some.
 
Forgot one thing. I do veg my plants for a period of time in the flowering room. My veg was a little lacking so i would start em off in one gallons under 600watt MH then transplant into there final 7 gallon pot and veg for another month in the flower room. So they have been vegging using co2(800-1000ppm) without fresh air. Again another topic that i don't see anything about.

I have since then improved my veg space to allow me to grow plants in there final pot and be ready to transition directly into flower without additional veg time in the flower room.

:)
 

ghostmade

Active member
Veteran
Just vent your room at night.especially if you're running soil.also have a couple fans above and below your plant canopy.also have a couple blowing(oscillating) directly on the plants.
also on the side note about the fans below the canopy, make sure to adjust your drippers,especially for those nearest the fan,to offset the increase of evaporation.
or just grow hydro ;).put ur control and reservoir outside of the room.also look into those HEPA filters you put over your inlinefan. I think there called dust shrooms.
anyway just take my advice with a grain of salt I'm just some guy on the internet who be lurking.lol good luck
 

Avinash.miles

Caregiver Extraordinaire
Moderator
ICMag Donor
Veteran
bump for views... I don't run sealed rooms but saw this in my lurking and have some of the same questions for sure.
 
Just vent your room at night.especially if you're running soil.also have a couple fans above and below your plant canopy.also have a couple blowing(oscillating) directly on the plants.
also on the side note about the fans below the canopy, make sure to adjust your drippers,especially for those nearest the fan,to offset the increase of evaporation.
or just grow hydro ;).put ur control and reservoir outside of the room.also look into those HEPA filters you put over your inlinefan. I think there called dust shrooms.
anyway just take my advice with a grain of salt I'm just some guy on the internet who be lurking.lol good luck


Are you sure you are replying to the correct thread?

I have plenty of oscillating fans, my ac is constantly running which thoroughly mixes the rooms air and had a 1400cfm max fan with a carbon filter running 24 hours a day mixing and scrubbing the air.

I hand water in soil, been doing that for years an i actually prefer it. Kiss method goes a long way for me.

When i do reinstall my intake, it will be filtered and will have a damper.

Thanks
 

ghostmade

Active member
Veteran
Sorry bro,I must of overead it. I was encountering the same problems with weak stems and smaller knots after super cropping.my yeild was on par with the unsealed room. .7 to .8 gpw...now, after I started to vent at night my problems went away.yeilds went up a unit(totaling 7 units strain depent) this was an a 10 by 10 room.16 plants in 30 gal rols. Critcal shunk.
and that funny smell or anaerobic smell is due to low levels of oxygen in the media.
 
Hmmm. Have you tried checking your co2 controller to see if it is calibrated right? IDK. I`ve had them do some crazy sh*t. Hard to tell how much gas you are really using when it`s plumbed to the house. The bottles will tell you if the controller is whacked by staying too heavy or emptying too quick. Never tried a sealed room set up like yours. I either exhausted at night or ran flip/flop rooms with a lung. Both ways worked great. Don`t give up on co2 enrichment...
 

Mikell

Dipshit Know-Nothing
ICMag Donor
Veteran
FWIW, last time we ran sealed, we vented at lights out and exchanged air a little less than once an hour during lights on.

Spurr has a few posts on CO2 here, and IIRC, explains the problem with high CO2 at night. Slipped out with the ear wax.

If it is the burner/oxygen levels, it may not produce enough CO to trip the alarm or visually impair the flame tip, but still produce enough ethylene to effect growth. You can check symptom against this or that.
 

Zarezhu

Member
Could it be old bulbs/old hood? The reflectivity of the hood diminishes quite a bit after a year or two of housing a 1000w bulb inches away from the aluminum. Old bulbs also have significantly diminished output. Both of those problems are not necessarily visible to the naked eye, but are legitimate issues.

Another possibility could be the clone? Some old timers I know SWEAR that the DNA in a clone degrades after time, saying the genetics lose potency and vigor as they age. I don't have first hand experience with old genetics, so I'd take that with a grain of salt. It just seems more like a bad excuse.

Does natural gas possibly have any possibly toxic byproducts when burned? I'm about to purchase a co2 tank myself, but only because I don't want to introduce any extra heat (pilot light for propane burner).

I'm in the process of building a sealed room myself, and would HATE to run into major issues. The musty smell definitely has to do with the mushrooms. Fungus can be an overpowering odor. High fungal content is GREAT for flowering plants in an organic grow. Do you aerate your water?
 
F

fishwhistle

My guess would be ethylene from the burner,I use bottled now just for that reason.Ive heard this happen to alot of people and the cure is fresh air during lights out or switch to bottled co2 or both.
 

Granger2

Active member
Veteran
I'll bet that a UV-C Air Purifier would help or even fix your problems. Get one that does not produce Ozone. Amazon has a bunch of them of course.

I bought 2 of these, and plan on 2 more. Need to replace bulbs every 6 months.
http://www.amazon.com/GermGuardian-...rp_a1_2_p?ie=UTF8&refRID=1XPMWFQG5EW4JY19FACK
One of these will treat the volume of air in my room in slightly over an hour. Put the other one in my drying room. There are of course many larger capacity units for larger rooms than mine. Prices on many are pretty reasonable, and could be a low cost solution for you. Good luck. -granger
 

theother

Member
Bottled gas ftw! It's worth trying, you probably have a tank around, if not it's worth buying one, reg is cheap. It can make a difference.
 
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fulltimehuman

Active member
One other thing with the night venting it may be wise in the AM to allow the lights to come on fully and let the stomata of the plants open up before raising up the Co2. i have read reports here on ICMag about high Co2 levels before stomata opening tend to keep them closed because there is so much co2, and this can diminish growth and yields. makes sense.
 

EclipseFour20

aka "Doc"
Veteran
What you have is what I call the "bad breath" syndrome...aka "lack of air exchange". I vent my closed environment with fans sufficient to exchange the air (based on cfm) the equivalent rate of around 13 times per hour--which works for me; during lights off the exhaust fan cycles on three times for 1/2 hour at a time.

Formula: Air Changes Per Hour = CFMx60 (fan rating) / Cubicfeet (room)

Assumptions:
Fan: 200 cfm
Room size 10' x 13' x 7' (width x length x height) = 910 cubic feet

Answer: 13.2 Air Changes Per Hour = (200 x 60)/910

With higher ceilings you also have a greater number of "cubic feet" which means more work for the exhaust fan(s). Greenhouse systems usually prefer 1-5 times air exchange per hour (summer vs winter rates)...but that is not a closed environment and that usually means 24/7.

I use electric dampers to close the exhaust duct when lights are on--no reason to let the CO2 escape.
 

frankenstein2

Astronaut Status
Veteran
Quote- " Somehow the plants are not producing enough oxygen to keep up with demand without replenishing the air? Possibly the burning flame from the co2 burner is eating up plants oxygen? "

I have run a sealed room for quite some time now. Only 5 k, not 8k. But......plants use co2 as part of their grow process, and produce oxygen as a by-product of photosynthesis. If you have a dehuey and ac, there should be no need to vent the room. My guess is that your co2 controller is out of whack. I had a similar problem, and that was the cause. Co2 controller was showing the room was at optimum levels, and the burner wasn't working like it was supposed to. After further inspection, the burner was working when I turned it on manually. Unhooked the controller and put the burner on a timer, plants responded with immediate explosive growth. This is just my experience...........results may vary.
 
Thanks for all the replies, sorry for me delay. Enjoyed a nice weekend of nothing but disc golf and relaxing. Now back to the regular scheduled programming.

Hmmm. Have you tried checking your co2 controller to see if it is calibrated right? IDK. I`ve had them do some crazy sh*t. Hard to tell how much gas you are really using when it`s plumbed to the house. The bottles will tell you if the controller is whacked by staying too heavy or emptying too quick. Never tried a sealed room set up like yours. I either exhausted at night or ran flip/flop rooms with a lung. Both ways worked great. Don`t give up on co2 enrichment...

I have double and triple checked the calibration of the meter(titan atlas 3) seems to be on point. Dont worry i never give up. Really just want some solid info on how completely sealed rooms work. Thanks

FWIW, last time we ran sealed, we vented at lights out and exchanged air a little less than once an hour during lights on.

Spurr has a few posts on CO2 here, and IIRC, explains the problem with high CO2 at night. Slipped out with the ear wax.

Thanks, ill check those out.

If it is the burner/oxygen levels, it may not produce enough CO to trip the alarm or visually impair the flame tip, but still produce enough ethylene to effect growth. You can check symptom against this or that.

Again thanks, after all the reasearch i did on using a natural gas burner i read nothing about ethylene but i figured there has to be some by product that the plants dont like. Again i would have never chose that design if the information was there. You would think that the burner companies would give out this information when you but the product. I found NOTHING about using burners in sealed rooms. On paper it sounds awesome.

Could it be old bulbs/old hood? The reflectivity of the hood diminishes quite a bit after a year or two of housing a 1000w bulb inches away from the aluminum. Old bulbs also have significantly diminished output. Both of those problems are not necessarily visible to the naked eye, but are legitimate issues.

Another possibility could be the clone? Some old timers I know SWEAR that the DNA in a clone degrades after time, saying the genetics lose potency and vigor as they age. I don't have first hand experience with old genetics, so I'd take that with a grain of salt. It just seems more like a bad excuse.

Does natural gas possibly have any possibly toxic byproducts when burned? I'm about to purchase a co2 tank myself, but only because I don't want to introduce any extra heat (pilot light for propane burner).

I'm in the process of building a sealed room myself, and would HATE to run into major issues. The musty smell definitely has to do with the mushrooms. Fungus can be an overpowering odor. High fungal content is GREAT for flowering plants in an organic grow. Do you aerate your water?

Nope bulbs are all brand new. Hoods are as clean as could be with no glass.

Nope cant be the clones, been growing these strains for a long time and in multiple locations. Currently these same varities are killing it at the other spot.

I have read nothing about the natural gas producing anything bad, only if it does not have enough oxygen to burn then they can produce carbon monoxide. But not to say its not possible. I would really think manufacturers should provide that info. I have asked a lot of people this question, no one seems to know. I have an alarm in my grow and upstairs just incase. The Sentinel burner is the "NG" series for natural gas. Running it off my house is nothing abnormal at all. The burner does not actually run that long during lights on(maybe a minute every 20 minutes). No pilot light either, electric start.

Ya i am a huge fan of mushrooms but in all my days of growing i have never seen this much fungus in the soil, def smells like mushrooms. Something is not right there.

Whats the humidity in the room during lights off?

Humidity maintains around 40% percent with lights out. The quest dehumifier is bad ass!!! If your ever in the market check them out, they pay for themselves in about a year over your typical frigidare type units.

I'll bet that a UV-C Air Purifier would help or even fix your problems. Get one that does not produce Ozone. Amazon has a bunch of them of course.

I bought 2 of these, and plan on 2 more. Need to replace bulbs every 6 months.
http://www.amazon.com/GermGuardian-...rp_a1_2_p?ie=UTF8&refRID=1XPMWFQG5EW4JY19FACK
One of these will treat the volume of air in my room in slightly over an hour. Put the other one in my drying room. There are of course many larger capacity units for larger rooms than mine. Prices on many are pretty reasonable, and could be a low cost solution for you. Good luck. -granger

Already got one, its called a REME. Plasma uv light that does not produce ozone. Got this a few grows ago thinking it might help. Did nothing that i can see at least. Since they produce light that means i had to duct out my AC with insulated metal ducting so that light does not bounce off the metal ducting and cause potential hermies. Cost me over a $1000 to get the Reme and ducting installed. ANd it was not the problem. LOL.

Quote- " Somehow the plants are not producing enough oxygen to keep up with demand without replenishing the air? Possibly the burning flame from the co2 burner is eating up plants oxygen? "

I have run a sealed room for quite some time now. Only 5 k, not 8k. But......plants use co2 as part of their grow process, and produce oxygen as a by-product of photosynthesis. If you have a dehuey and ac, there should be no need to vent the room. My guess is that your co2 controller is out of whack. I had a similar problem, and that was the cause. Co2 controller was showing the room was at optimum levels, and the burner wasn't working like it was supposed to. After further inspection, the burner was working when I turned it on manually. Unhooked the controller and put the burner on a timer, plants responded with immediate explosive growth. This is just my experience...........results may vary.

Since this topic has been brought up multiple times it cant hurt to quadruple check it. :)

I agree with your first statement and is the exact reason i posted this thread. Im okay with installing an air exchange on the room again, i still even have my equipment from before. On paper the selaed room should work but in my space it does not seem to. Maybe its the burner. Ill see what exchanging the air hourly does. I think i can still run the burner with that design. The burner fills my room pretty fast.

What you have is what I call the "bad breath" syndrome...aka "lack of air exchange". I vent my closed environment with fans sufficient to exchange the air (based on cfm) the equivalent rate of around 13 times per hour--which works for me; during lights off the exhaust fan cycles on three times for 1/2 hour at a time.

Formula: Air Changes Per Hour = CFMx60 (fan rating) / Cubicfeet (room)

Assumptions:
Fan: 200 cfm
Room size 10' x 13' x 7' (width x length x height) = 910 cubic feet

Answer: 13.2 Air Changes Per Hour = (200 x 60)/910

With higher ceilings you also have a greater number of "cubic feet" which means more work for the exhaust fan(s). Greenhouse systems usually prefer 1-5 times air exchange per hour (summer vs winter rates)...but that is not a closed environment and that usually means 24/7.

I use electric dampers to close the exhaust duct when lights are on--no reason to let the CO2 escape.

Yup, setting the air exchange is in the works, was trying to determine how often i should do it so thanks for information. I am using dampers as well to make sure im not losing the co2 when not exchanging air and to also keep my ac from pulling in air when not needed.

Thanks for all the replies, my gut really is telling me i need to exchange the air. But what is driving me nuts is that this type of grow design should work but the results for me are proving me wrong. I want to find someone that can really explain to me why my room would be anaerobic when i am expecting my plants to be producing oxygen.

You guys are awesome, i think this is a good thread and hope this can help prevent and resolve problems for others. Trust me this has really made me question my abilities but i guess when you enter new realms there will be trials and tribulations.
 

Mikell

Dipshit Know-Nothing
ICMag Donor
Veteran
FWIW, I also read about this afterwards. We were exchanging air during light cycle on the recommendation of our gasfitter after installing 12-head burners on NG.

If you record how often the unit is running, you should be able to work out a formula for desired oxygen in cubic feet, and us that to fine tune exhaust. This is mild conjecture, but a conversation with a gasfitter or burner manufacturer should clear up any gobblydegook. A solid internet search and an ounce of mathematics may provide similar result, but I would still confirm with a specialist.
 
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