First time questions

[OkieDan]

I live in OK and expect to receive my medical license by end of March. I've been trying to decide the best way to grow year round. I plan to grow in my shop which is not heated or cooled. I'm thinking of building an insulated room in the shop and cooling it with a window unit and probably heating it with a propane wall heater (semi-free CO2 in winter). I think it will be easiest to maintain a good climate by taking hot air from the tent(s) through a carbon filter and mixing that with the conditioned office air, as opposed to venting to outdoors which would require the same amount of outside air that could be 20° to 115°F with varying humidity to come back in. This leaves me with a CO2 problem...

Are these the only things I need besides a bottle (and a spare) of CO2 to maintain proper PPM:
Enly Controls Day/Night C02 Controllers W/High Temp Shut-Off & Display

KIPA CO2 Regulator with Solenoid Valve and Flow-Meter Emitter. Accurate Gauge 110V, C02 Emitter for Indoor Gardening, Aquariums and Hydroponics

Legally, I can have 8oz dried marijuana, 1oz concentrate, 72oz edibles, and finally 6 mature plants and 6 seedling plants, legally defined as:
"Mature Plant": means harvestable female marijuana plant that is flowering.
"Seedling": means a marijuana plant that has no flowers.

I take this to mean I can have 6 plants in flower and 6 plants of any size in veg, would anyone disagree?

I was thinking about getting a 4x4 and a 2000w Phlizon LED (308w input) and doing veg and flower in same tent. Should I do a couple 2x2's instead with smaller lights to have a steadier supply of lower yields to stay under 8oz max dried marijuana?

 

[George Mc]

I don't know anything about the CO2 question but in case you're not aware 1 or two plants can easily produce 8 oz. If you're very novice and screw things up you might be able to get 8 ounces out of four plants. From what little bit I know about your law I would probably grow two plants inside of a 2 x 4 tent. I think you would be safe. Others will chime in here with their opinion

 

[Aroxol]

Couple of quick conceptual things.

1. CO2 is really designed to be used in a sealed room, meaning climate is good inside the tent so you’re not exhausting hot air. If you’re planning to run exhaust fans, CO2 isn’t a good fit because you’ll suck it all out before the plants can absorb it.
2. You’ll need separate grow spaces for veg and flower generally speaking. This is because unless you’re running autoflower plants... plants in veg require 18-24 hours a day of light, whereas flowering plants require 12 hours of light. If you have all plants in the same room and set your light to 12 hours a day, all plants will start to flower (assuming they aren’t auto flower).

 

[OkieDan]

Thanks for the replies! I don't want to use auto-flower, as I do want some control over things (especially the number of plants on property that fit the legal definition of "mature").

A couple 2x4 tents sound reasonable, I'll downsize the light just a little and get two.

CO2 is my biggest hurdle. How do I maintain good temperature and humidity and sustain an adequate level of CO2? I am ok with abandoning the idea of the tents exchanging air with the office, and just having the tents exhaust air to outdoors, but ultimately, the tents will have to get fresh air back into them. During the Winter and Summer, that would be fairly cold/hot air with an unknown humidity. At what rate (CFM) would I need to exhaust air from the tents to keep CO2 levels adequate? I think I would need to know this so I could determine the qty of air I would need to condition before being added back to the tents.

 

[Aroxol]

You don’t have to supplement CO2 into the grow area, it’s an optional thing that improves yield in specific scenarios, but not necessary. If you’re going to pump heated air that already has CO2 into the room, it doesn’t really matter if you exhaust it out as it’s just the setup you have. As long as the room doesn’t exceed ~2000PPM of constant CO2 you won’t have a problem. Fresh air will always find a way to get into the grow room no matter what. I have no intake fans in my setup and have never had a problem.

For your first grow, I would not invest in CO2 regulator or controller. Just grab some tents and lights and as the grow goes on you’ll determine what you need.

 

[Aroxol]

I’d probably actually only grab one tent and one light and do a full cycle grow.

 

[OkieDan]

OK, I'm going to make a room that is probably 10x12 and have a window unit condition that room and add a tent or two. You think I won't need to add supplemental CO2 in such a small room and will be fine with simply exchanging the air in the tent with the air in the room? During the winter I see this working fine with a propane heater, but I'm a little worried during times when temps in room stay warm enough that wall heater does not kick on.

 

[George Mc]

If you're getting a 2 by 4 tent you'll need a 4in inline extractor fan with carbon filter if you want to stay discreet. A four-by-four you can use a 6in or 8 inch exhaust fan.

 

[Aroxol]

You’ll be good without supplemental CO2 for sure.

Air temp, humidity, distance of light from canopy, and making sure pests don’t get in are priority #1

Smell comes into play down the line.

CO2 is last on the list.

 

[OkieDan]

Thank you both, I'll quit worrying for now. I definitely want good control of temp/humidity and such, which made me want a sealed room with no exhaust to outdoors, which had me worried about CO2 due to lack of exchange with outside air. I'll see how things go without doing anything for CO2 for now. The light thing should be easy to handle with some basic diagnosis of symptoms (stretching/bleaching). I took over pest control last year and have things that work well that I won't spray on the plants, but will have shop, yard and home sprayed down, so I shouldn't track anything in. I will have to see what options there are on sanitizing potting mix besides heating it up inside the house. I'll have more time to read up on many other questions before I have this room built, but this CO2 question was something I was having an issue finding information on.