Many questions about grow room setup

Hi there, i am a first time medical grower (with all proper paperwork) and am in the process of setting up a grow area for my meds and those i am caretaker for.

I have attached an image of my setup that i am in the process of building. I will have two 4'x3' "rooms" (one for veg, one for bloom) and one 2'x3' area (for clones and seed starting). I will be putting together a PVC frame and building the walls with panda film (black/white plastic sheet). I will add foam insulation walls if needed to keep heat in during winter. (will probably grow outside in summer)

I have a bunch of questions i'd like to ask before i start moving ahead with my plan, if anyone can help me out!

- Ventilation is something i still have a lot of questions about and my main concern. I have access to a small window right near the top of the grow tent as show in my image. Because i live in a climate that has cold winters, will i even need to bother venting out the window? From what i have researched, the LED lights dont put off nearly as much heat as the MH/HPS lights so i was hoping to just scrub the air and circulate it within the room the tent is located. I don't want to have to supplement with a heater because i am sucking in cold air from outside unless its a must.

- Any suggestions on air intake and exhaust vents? How much air do i need to be circulating in each "room"? What size vents, 4", 6", 8"? I assume i would want my air intake on the floor or near bottom of the tent and the exhaust at the top since heat rises.

- I will also have a small oscillating fan in each room to keep a breeze going, any suggestions on size fan for each 4'x3' room?

- What size carbon filter and fan do i need to scrub the air in the entire area (3fx10ftx7ft). From what i have read i want to circulate the air 2x a minute. I can vent the air inside or outside, doesn't matter. Just want to use the carbon filter to cut down on smell.

- Do i need to consider anything in my design if i plan to incorporate a c02 system into the rooms?

- Did i miss anything or do you see any serious flaws? Any suggestions?

- What size and type lights would you suggest for the 2'x3' area i want to use for starting seeds and clones? I have a small 16 hole clone box, and a bunch of those trays with pete moss pucks that you start seeds in. I currently have two 4ft long ballasts that each have two "40 watt gro lux wide spectrum" florescent bulbs. Can i use these lights since i already have them? They were here from a previous owner so not sure if they are good for starting seeds and clones. (and they wont fit in my 2'x3' area).

It'd be more efficient if you ditched the separate flower veg rooms. And less environment headaches.

Don't put a partition in between the veg and flower room. Veg and flower in the 4x6 room.

Don't even consider CO2 at this point in time.

Skip the LEDs, get 2 600's

Its hard to estimate what size fan you need, without knowing ambient temps. Match carbon filter to fan at a minimum, most like to up-size the carbon filter.

- Jiji

Already have the LEDs so stuck with them at this point. Also, i was planning on doing sea of green method which is why i have the two separate rooms, is that still a good idea considering my grow method?

I would want more room than that. I had a 4x5 flower with two 600s and it was too cramped for my preference. Once my fan was in there, I hardly had room to do anything and certainly didn't have room for a dehumidifier once summer rolled around. The PVC and panda film will work, but I prefer real walls and you may too after a few harvests. Either way, make sure you don't have any light leaks.

The fluoro bulbs you have will work fine for the seeds and clones. If those go out you can use regular pigtail cfls for starting seeds or rooting clones.

I assumed that you were building this within another room. Realistically, the area may not be air tight, so you may want to calculate for scrubbing the entire containing room (not just your 3x10x7 tent), but I'll leave that to people who scrub (my med cards are my scrubbers...I love the smell and live in a nice neighborhood so I don't worry about it).

Make sure that when you are reading you are reading about LED grows. What I am saying is that you should not expect your plants to grow as if they were under HPS lights. For instance, under a bunch of HPS lights, you may want to replenish CO2, but are LEDs different? I didn't read anything about a dehumidifier and under high powered HPS, you might burn enough off during lights on to carry you through lights off, but with LED you won't be burning off any humidity - from what I know. LED grows seem to have their unique problems, so just make sure you are getting advice from LED people when doing your planning....see, I'm not an LED person so I shouldn't be here! Good luck though.

Thanks for the advice, very helpful. The tent is going to be setup in a basement, the reason i am going with a tent before i put up permanent walls is for flexibility in case i want to move it. Once i find a location i am happy with, i will more than likely put up a real wall around it.

The LEDs i have cover a 4x3ft area which is why i went with those dimensions (and i am tight on space). Since they are LED and this is my first time around, i figured more light in a smaller space would be better than going too big and having to add in more lights. I have a friend with the same lights just a much bigger setup than mine, he is also helping me along as i go since he has done many grows in his days.

As for humidity, i don't really have a humidity problem in my basement as of right now. But i do have a dehumidifier i can run to keep the entire basement in check if it becomes a problem.

Will i be OK venting the air into the basement or should i be pulling in fresh air from outside? My only concern with pulling in air from outside is that its freezing in the winter where i live and i will probably have to put a space heater in to heat the air before it goes into the tent.

I will speak to the oscillating fan question. There is no way you are going to want to mount an escalating fan in each of those rooms. They take up a lot of room. Keep the air circulating with small office desk style clip fans. You need to keep air moving and not necessarily oscillating it.

As for ventilation. You can vent your grow room right back into the basement. The constant recirculating of air can mean a wicked humidity increase over time. You might need to run the dehumidifier.

You can vent both rooms with a single in line centrifugal fan if you want too. You would cut intake holes at the bottom of the flowering room. Typically you can run 2" PVC at three 90 degree angles in order to prevent light leaks. Then you would do the same thing where the two tents meet and pull air through the flowering room into the veg room. Three 2" PVC holes should allow air to flow really good for a 6" fan.

Inside the veg room you can hang a filter at the top connected via ducting to wherever you want to place your exhaust fan. The fan doesn't necessarily need to live in the grow room. It can be mounted outside the room as long as the duct work is good.

A can fan rs6" will consume 1.15 amps and move 392 cfm. It will cost you around $180. Pair that with a 6" 550 cfm phresh filter $175 and you should have no smell as long as things are air tight. With passive venting there will always be some smell unless you run the exhaust fan 24/7.

Most people pair exhaust fans with a temperature/humidity controller that will turn the fan on as needed. If you are lucky you can put the controller in one room and set the temps and it just might keep both rooms within a reasonable growing temp range.

As for what jiji wrote.

How can he get rid of the partitions assuming flowering is on 12/12 and veg is on 24/0 or 18/6?

And if the fluorescents don't fit then you probably need new lamps for that. Just remember before you order stuff to check the dimensions of the lamps. A 2ft 8 lamp sun blaze would probably work well in that area. $200ish. You can clone and veg under the same lights if they run 24/0. You will need to shade the baby clones though because they don't require much light at first.

You can always unscrew some bulbs too if you need too.

Thanks alot for the replies, you all have been very helpful. I was actually thinking of that very setup you suggested. Please see the image i have attached.

Do i need to make sure the holes between the walls are sealed? What i mean by that is, when i make my walls i am just going to loop panda film around the 1" pvc to create walls (and duct tape the corners), so there will be a 1" air gap between each side of the plastic inside of the "wall".

Am i OK just cutting a couple 2" holes staggered as i mentioned in my picture, or will this encourage mold and other crap to grow in between the "wall". Am i better off using some ducting or PVC to create the hole between the flower and veg and clone walls?

Want to make sure i do this right the first time.

Spirallight said:

As for what jiji wrote.

How can he get rid of the partitions assuming flowering is on 12/12 and veg is on 24/0 or 18/6?

Click to expand...

I meant veg the crop then flower it in the same room all at once.

With LEDs and the desired set up, environment should be super easy to manage. However I think your gonna be disappointed come harvest time. It's up to you, maybe that’s all you and your patients need.

- Jiji

jijiandfarmgang said:

I meant veg the crop then flower it in the same room all at once.

With LEDs and the desired set up, environment should be super easy to manage. However I think your gonna be disappointed come harvest time. It's up to you, maybe that’s all you and your patients need.

- Jiji

Click to expand...

What exactly are you thinking my yields will be? This is my first grow and using the much hated LED lights, so i am not expecting to knock it out of the park my first try.

How can i maximize my use of space? I was planning on going with the sea of green (SOG) method, and having several rows of plants in each area (veg & flower) and cycling them every 2 weeks so i have a continuous harvest. From what i have read, i want 4 plants per square ft so that should give me about 48 plants in each main tent. Once i get this process nailed down i will probably setup some hydro tables and grow that way.

If i can net at least 7grams from each plant and crop 12 every 2 weeks, that's about 6oz a month.

Are there other methods i could use which would give me a better yield? The main reason i am against growing it all at once in a big area is i'm waiting 3-4months until i can harvest. I much prefer a steady supply. Plant counts are not an issue for me the way our laws are written (excluding feds).

about a pound

lol just kidding, I dunno.

I suppose there's 4 real keys to yield. Growing healthy stress free plants, lots of light, good genetics, even full canopy (pretty much requires monocropping.) Hydro almost belongs on that list but its probably less important.

Not an led person, and I don't even know what leds your using. Either way they don't have nearly the penetration of HID so if you want a half way decent yield you will have to do scrog or even canopy sog.

- Jiji

Thanks Jiji, will let you know how i make out once things are in full swing.

Any suggestions on my questions regarding the venting between the walls of the grow room?

If this is truly your first setup then there is no way you are going to get it right and dialed in your first try. The 1" gaps are not an issue. The design looks fine but remember you need to keep negative pressure to keep that filter working. The seams also need to be taped so you are just drawing air from the passive intake vents.

Thanks for the clarification jiji

Thanks for the tips Spirallight! If this panasonic whisper fan ends up working for what i need, i plan to run it 24/7 to keep the negative pressure in the tent.

Your welcome and good luck!

You may want to consider shifting the wall over a foot and giving yourself a little extra room in flower, and a little less in veg.

I also grow in a small space (2x4x7), I use that tent for flowering, and have a little 2x2 cabinet that I use to root my clones. I cannot do a true perpetual, but I can keep clones in the small cab until my flowering is done, then shift the clones over to the 2x4 for a short 2 week veg and flip lights back to 12/12. In a 2x4 I can fit about 6 plants if I keep them really small on a 2x3 ebb and flow tray.