[TrichCrazy5280]

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.

[TrichCrazy5280]

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]

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]

bump for views... I don't run sealed rooms but saw this in my lurking and have some of the same questions for sure.

[TrichCrazy5280]

Originally Posted by ghostmade

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]

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.

[ghostmade]

Forgot to add the roo.was 4 k

[bushdoctor215]

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]

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]

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?