Advantages of a SEALED room...

shirami said:

http://www.autogrow.com/index.php/general-info/humidity-and-vpd

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Thanks Bro....Even though this is a "greenhouse based" explanation , it plainly states what I learned from Krusty about elevated RH levels back in the day of at least 70% till end of stretch , and then as low below 50% till end of cycle is what`s needed for dialed environment for growin dope.....and then a few yrs later......

Heath Robinson let it be known that air exchange twice per minute with active intakes and exhaust scrubber combo`s helped to ease the a/c needs , as well as keeping condensation from forming during lights off when the plants shit out all CO2 they didn`t use during lights on along with the excess humidity .......

Ambient lights on/off temps within 10 degree variables to prevent condensation is a big rule of thumb as well through the life of the grow.....

VPD/Proper RH/Environmental control with proper watts per sq ft start to finish FTW......Thanks for the link Shirami , and the thread as well Third Coast....but......

There are other ways to run other than sealed with advantages as well.....

Peace...DHF..........

What happens if humidity stays high right until the end of flower, I am running perpetual so it's either one or the other?

Is it only to discourage bud rot that humidity is lowered after stretch?

I just finished my run with rh getting up to 86 in the last week (up to 94 during night in the weeks previous) didn't have any trouble with mold as I had lot of air circulation. Not recommended though as I think I was lucky. I'm gonna run my room with a dehumidifier set to come on 80 cause i know my strain can handle it

i run a higher temp and humidity during veg, and dont worry about managing humidity until week 3 or so. I was venting my hoods on my last grow( 1st grow in 5 years) and running co2 with a hot water heater and really had no problems with leakage, the hot water heater is a cheap badass way to supplement, best bang for a buck imo. i ran blue dream and when i got lazy about humidity i payed for it with a ton of pm

adz007 said:

I just finished my run with rh getting up to 86 in the last week (up to 94 during night in the weeks previous) didn't have any trouble with mold as I had lot of air circulation. Not recommended though as I think I was lucky. I'm gonna run my room with a dehumidifier set to come on 80 cause i know my strain can handle it

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You truly are the exception and most definitely not the rule , and as long as air is exchanged in and out of the grow areas constantly , the risk of airborn pathogens are negligle....but.....

With RH well above 50% during late flower is a crapshoot/roll of the dice at best from all the nightmare stories over the yrs about total crop loss from Grey mold/Botyritis/Powdery mildew, etc , etc.....

The question about running perpetual in the same room is a good one since most folks run 50% constantly and suffer through veg and stretch without proper elevated RH , but keeping the finishing plants within parameters of not having to worry about said airborn pathogens with proper air flow and circulation/extraction till end of cycle.......

Most all my old head growbro`s at the med sites have gotten away from CO2 supplements yrs ago and employed the air exchange twice per minute into and out of lung rooms , but CO2 has it`s place where yas don`t own the property and or don`t have a way to produce perfect environment "outside" the grow areas to be pumped into and sucked out of twice per minute........

Many ways to skin a mule.....

Peace....DHF....

I run sealed rooms with bare bulbs and I"ll never go back.Having complete control of enviornment and consistant heavy yeilds of a dialed in co2 enriched room is well worth the added costs, not to mention the added security.

For those who are just getting into sealed room you will need a serious dehuey,such as a Dryeez,Santafee,etc in the $1500-2000 range for a 4-6kw12'x12 room,thats the pricing in my area anyhow.The a/c heats my house all winter.

Cheers PB

DHF I read what you said about info being lost on other sites through the years!

I feel that proper documented grows proving claims of super high yields is lacking here on icmag. Even the farm was better when it came to this!

Well now that I'm at week 7 with some chem lines I'm going to say lack of smell is a BIG advantage.

I have this exhaust fan right above my room venting the barn and there is absolutely no smell that gets out.



I have a filter ready to go when needed but I'm starting to think it will be used in the drying room instead of the flower room.


DHF, in this scenario you're talking about with the air exchange 2x per minute, is the lung room not sealed? If it is, I would consider that to be a sealed room.

Third Coast said:

Well now that I'm at week 7 with some chem lines I'm going to say lack of smell is a BIG advantage.

I have this exhaust fan right above my room venting the barn and there is absolutely no smell that gets out.

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I have a filter ready to go when needed but I'm starting to think it will be used in the drying room instead of the flower room.


DHF, in this scenario you're talking about with the air exchange 2x per minute, is the lung room not sealed? If it is, I would consider that to be a sealed room.

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Hey TC.....My lung rooms were sealed "per se" in that there were filters over the intakes and scrubbers with "pre-filters" on the exhausts , but not sealed as in hermetically like a mayonnaise jar with all things happening inside the grow areas with CO2 supplements and all other environmental control with industrial dehuey`s and minisplits to control said sealed room/s....and....

Moses , The biggest factor in growing with sealed rooms is that you have to use CO2 supplements for the plants to SURVIVE since plants eat CO2 and shit oxygen , and that`s the ONLY way a sealed room will function......now......as far as those blown up yields in sealed rooms , I can honestly say that......

I`ve NEVER seen a setup on ANY public weedsite in 20 yrs + including the farm that ran ambient temps high enough while controlling relative humidity to accelerate the plants metabolism/transpiration/increased nutrient uptake with CO2 supplements except 1.....and....

That was Krusty the krazy ass klown waaay back in the day with tanks/controllers and spaghetti tubing and holes drilled in and looped around the tops of all his 3+ lb monsters pumpin out colas the size of 3 ltr coke bottles consistently run after run.....but...

He STILL exhausted all his "lights off" environment with big ass exhaust/scrubber combo`s up high in his warehouse grows to prevent airborn nasties forming from the outrageously increased humidity and CO2 the plants didn`t assimilate during lights on , although many folks were never privy to that information on his "so-called" sealed rooms.....anyways......

Sealed rooms work.....Not many folks know how to dial em and exploit the plants by increasing ambient room temps to initiate a higher metabolism/transpiration/nutrient uptake rate for "true" increased and once dialed bottom line results.....but.....

All about what works and is proven compared to what most folks perception is of what works.......Sealed rooms do indeed help to secure grow areas and keep one from paranoia , but major air exchange twice per minute that I learned from Heath Robinson long ago do indeed perform the same functions without as much amperage draw and dialed results once environment and proper watts per sq ft are concerned IME.......regardless.....

Remember this....IF you seal your room , you MUST provide CO2 supplements for the plants to live ......period.......whether or not you dial said grow area and elevate temps and humidity to in fact produce superior yields and consistent returns is based on runs under yer belt and doin this shit.....

Krusty ran 70% RH till end of cycle , but he also ran nasty ass sulphur burners in late flower to prevent PM and other airborn nasties from takin over 30+ lb rooms outta 10KW , as well as the lights off exhausts for insurance.......anyways....

Just tryin to keep things in perspective......Not trying to sway folks opinions on which way`s best for their personal grow setups , just keepin it real and factual......

Peace....DHF..........

What if your room is closed without co2 and your co2 readings are 500-600 at all times?
I think it was SuperStoner on Stinkbuds site that ran sealed for years without co2. I think he finally added it and increased yields though.

TribalSeeds said:

What if your room is closed without co2 and your co2 readings are 500-600 at all times?
I think it was SuperStoner on Stinkbuds site that ran sealed for years without co2. I think he finally added it and increased yields though.

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Thank you Jesus........You too TS......LOL....

CO2 ppm`s are ever present in the air we breathe , and are usually ambient around the 450 -750 ppm range depending on how polluted your air is from the factories shittin out the excess from their manufacturing processes.....that said...

SuperStoner NEVER ran without CO2 , it was only without CO2 "supplements" he ran without ok ?.....

Lower or higher ppm`s are subjective at best as far as to how it affect`s bottom line results and returns from what I`ve witnessed first hand IME......750-900 ppm`s dialed my shit for many yrs`swappin air out twice per minute.......

Peace....DHF...........

I think my water heater is dumping extra co2 into my garage. Although my grow room is also a few feet from a busy intersection

Remember that any decaying matter releases co2 as it decomposes, organic soil provides constant 600 ppm when I turn the supplementary co2 off, in my sealed room. As well as the co2 that has built up during lights off!

moses wellfleet said:

Remember that any decaying matter releases co2 as it decomposes, organic soil provides constant 600 ppm when I turn the supplementary co2 off, in my sealed room. As well as the co2 that has built up during lights off!

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I am willing to stick my neck out and say that there is no way any soil will pump out enough CO2 to feed a proper multi light garden. If you measure it within 30 minutes of lights on, yes, of course you will have CO2, because you all understand the fundamentals of photosynthesis right ?

Plant growth is governed by limiting factors, growth is only ever to the extent of the most limiting factor....i.e. if just one thing is "wrong"... 5/10... growth, yield, is 5/10. A 5/10 crop, yield can be very impressive, but unless you control all environmental factors, all the time, you will loose.

DHF is spot on IMO about the need to use raised temps and RH in the first half of flowering, and to lower it later on. Lots of great information here, really looking forward to setting a garden up like this.

Didn't mention that is in veg. I will do some more measuring too see if you are correct. But I have been getting excellent veg growth without any supplementary co2 since last year.

In fact I found that 1000 ppm in veg actually causes insane growth that is too fast and vigorous for my schedule!

Ive been running sealed rooms my enitire life. I have had two split for 6 years now.

I have a 3.5 ton central ac with open hoods. 20k including Veg.

There are two rooms and Veg. All linked together with duct and scrubbers. I have three scrubbers they run 24/7. I treid to run a dehumidi but didn't like all the heat it caused. So its another waisted peice of equipment.

Temps about 82 day 74 night RH day 55 night It climbs to about 75.
Run my CO2 1150 24/7 thats right when one room is sleeping they still are in the CO enviorment. I have not had issues with this method. I have a CAP burner. Love it with my rooms so sealed. I can breath them up to 1400. So the burner barly runs to keep the ppm a grill sized propane tank.(20 lb) lasts me like a month. Did the bottles for the first 10years of my life. Even used a torch head to burn CO back in the day.

Allot of my growing goes against everything I've ever read. I designed the rooms and gave it a go and never looked back. I couldn't run all the lights at once and keep up with the heat. So I split.

Ive never had an issue with mold. I run reused soil. Wet dry every other day waterings. 3 gallon buckets in veg. That I plant in beds for flower. Beds are always 12/12

While soil is amended with organic food and watered with tea only. I do feed the buckets on top the beds with Nova and various other additives.

My Av pull for 2k per week is 4#
Granted Ive seen better 2.5 per 1k or more. But if you factor in that I get 52 weeks a year. I match or blow numbers out of the water. Not to.mention other then rent and electric my overhead is null. Like $500 month for all my food.

I also water with AC water only. So I have no water bill.

I recently tried aptus with coco and while coco is nice the aptus is shit.
But thats another story.

Here is my same WIFI i got from a pack.

5gallon coco with Aptus


In my soil.
Both from my sealed rooms


Thank You
T~P

This is a great thread. Thanks for all who've contributed. I've always run non-sealed rooms, but am thinking about switching over. There are two things I hate about a non-sealed room. First, having the odor escape the room. With negative pressure all is well as long as the power is on, but whenever you lose power for more than a few hours (and it happens) you can first smell the scent escaping from cracks and pores in the room and from your exhaust because even with dampeners the exhaust is never 100% sealed. Secondly, it's expensive sucking all your heat in the winter/air conditioning out of the room in the summer as your changing atmosphere every 2-3 mins.
So I'm thinking if the room is sealed the odor will never leave the room, even if you lose power and its got to be cheaper because your not sucking hot air thru the intake and exhausting all your cool room air thru the exhaust in the summer. So I'm about ready to seal it up. Panda on all the walls, floor and ceiling should get it done. Then I just have to workout the c02 issue. AM I missing anything? Or is my logic off on the potential energy savings?

I always run a duct for my hoods. I cut two 6" holes. One for active intake and one for passive exhaust.

ALWAYS PUT YOUR BLOWER ON THE INTAKE SIDE OF YOUR LIGHT COOLING DUCT and you will never have any odor escape. You will also never deplete your C02 levels.

There will be positive air pressure in your duct and any tiny pinholes (if you do a shitty job) will be pissing out air, NOT sucking it in.

So it IS possible to slightly deplete your C02 levels if you have a crazy leak and the outside 300ppm air mixes with your enriched air.

If you take care while making your connections, you will have no leaks.

Use insulated flex duct in case outside air temps (if you're pulling in from outside) get extremely cold. If you do not insulate the ducts, they will sweat when filled with cold air and your warm humid grow room air will condensate on them. NOT GOOD.

This method DRASTICALLY cuts down on A/C usage.

Most of the heat generated by the lights is blown right out of your room.

Put one of these on the intake and you'll never have to worry about blowing mold spores or critters through your lights... http://www.growlightexpress.com/ind...uct_info&products_id=2007&cPath=50#googlebase

My 2 cents.

Am I right in saying that a dehumidifier works on the same principles as an air conditioner? The dehuey vents hot air out the back, but it also cools, so it shouldn't raise the overall temperature of the room. Aside from the obvious, that you don't want to vent the hot air directly onto your plants, make sure it is located properly!