Hi all. This will be my first time indoor grow. I am waiting for things to arrive at this point, but have a pretty good idea of how I'm going to go about this. I have attached an image below to better illustrate my plan. I am going to be running a 400w MH/HPS with air cooled reflector. Have between 4-6 auto ak47 going in a mixture of FFOF and pearlite using no extra nutes in 3-4 gallon pots. The box dimensions are 3'x4' and ~6' tall, lined with Mylar. 6 inch ducts with two 240CFM inline fans (one for light and one on box exhaust) I'm also considering putting the exhaust to room hole on the top of the box directly above the light instead of the top side. My main question is about heat, since this is my first indoor grow. I will be bringing outside air in to cool light, where the outside air will be on average between 60-75 degrees F, and taking that air right back outside. As well as drawing outside air into the box. The room that the box will be in will be a constant 60-70 degrees F .... very well insulated but not air conditioned. (the building is in the shade almost all day long) My main concern at this point is making sure this will be enough to keep box temperatures optimal, if anyone would mind sharing their experience on heat issues and all that jazz. (any other info about my plans would be greatly appreciated) Heat signature and odors are not an issue, i live in the middle of nowhere. (and have planned accordingly) I am curious about using nutes, but being autos i know they don't need as much, but still with myself being a relative noob, I would rather be safe than sorry. Thanks for taking the time to read/respond. Any input is welcome.
Looks like you are pretty on point. I don't think you'll have any heat issues the way you have it planned out. Can you test the setup before plants go in? That way you can make sure things are fine. Top side is fine for exhaust, no need for the actual ceiling. You can if you so desire though. For autos I agree, not very fond of heavy nutes. I would still monitor them as the nutes in the FFOF will only last so long. As to how long is anyone's guess, but probably a month or so if you start from seed. Maybe the plant won't use it all, but with all of the waterings I bet some of it will be flushing out.
Thanks for the response! I'm definitely going to give them a dry run for 16-18 hours to check temps and stuff, and to see how close I will be able to keep the light. The attic the box will be in is approx 600+ sqft all one room, and insulated well but not air conditioned, so I'm assuming the overall temperature in that space won't be too ridiculous outside the box. (I might exhaust the light duct into the attic also, just so I'm not putting that kind of heat outside) Also I'm going to put a 1 inch thick foam insulation board on the top of the box, just to be on the safe side. Being where I am I'm not too worried about flir, as people only really grow outside, and very rarely at all here. Maybe one chopper a year if any at all.
I think being able to test run the room will help a lot. Venting your light into the attic that size while also having your intake come from outside could work. You can also run the lights at night while having the dark period during the hottest part of the day. Assuming you're doing autos at 18/6 light schedule, I know some run 20/4 or 24/0.
Yeah 18-6 is optimum light schedule from what I've read.Maybe someone who grows autos will chime in. Are you able to grow outside too? I know if I was in the middle of no where I wouldn't even worry about an inside grow when I could be using free lighting! But Im sure you have your reasons, best of luck mate! Take pictures!
I was planning on running them 18/6 this time, see how it works out. was planning on having them off from either noon to 6pm or 1pm-7pm I'm deep in a valley, natural does work, I'm just trying to get a little better yield, and also have something I will be able to work with year round when needed. I'll for sure keep a journal on here. Thanks again guys for the info!
Hi I have grown Autos. But the main prob, if using HIDs, is the heat. You may need a powerful fan on intake to lamp. All the best. Haribol
The breeder should tell you which light cycle works best with their strain. Bomb seeds recommends 20/4 with their autos and they were right, I averaged ~100g per plant at harvest time. Here's the journal They were actually a very hungry strain and could've taken more nutrients than I was providing. OP you might want to consider using bat guano or Espoma tomato tone... I use both. As for your heat question, it depends on the type of fan you're using. If those fans are 4" 240cfm high-speed inlines that will work, but if they're 6" 240cfm duct boosters then you are going to have problems. I've tried, they don't generate enough pressure to overcome restrictions and the cfm rating is based on optimal conditions (boosting airflow that's already moving).
I got these from marijuana-seeds.nl last summer, which doesn't mention anything about lighting schedule. As of right now I was thinking going 18/6 for the first week, then bumping up to 20/4 for the remainder, or at least until the final week. I haven't gotten the fans yet, which was something I am still toiling over. They were planned to be the 6 inch 240, but I've been rethinking this. I'm basically going to set the cool tube up so there are only 6 inches of duct on either side of it actually inside the box, counting the fan. I was assuming or just figuring that if that would keep a decent bit of heat from the light out, that another one for exchanging air would be good enough. The box is 72 sq ft. ( 3x4x6 ) Would it be better to ante up and get one really bad ass fan and have one exhaust through the light? I am being some what of a cheap ass right now, trying to do what I can on somewhat of a budget, then eventually upgrade things within the month hopefully. I'm still trying to figure out what to do about nutes. I do want to use some. I grew this strain outdoors last summer in ffof and no nutes with great results, I was thinking about the ff trio or bio flores. I appreciate the input guys!
I would get 2x 6" inlines and speed controllers. That will handle anything from 400w to 1kw depending on ambient temps. That way if you plan on upgrading down the road all you have to do is switch your light and crank up your fans a little. You could probably get by with one 6" inline on full blast, but a lot of growers prefer to run their fans at half speed. This reduces noise and allows you to dial in your temps. I use Hydrofarm 6" inlines, they're $80 each on amazon right now with free shipping. The hydrofarm speed controllers (AKA "Active air") are $25 each, free shipping too and obviously match up with their fans (something to be aware of, fans and speed controllers can be incompatible).