First Grow Questions from a Noob :)

Discussion in 'Growing Marijuana Indoors' started by KeeNofGreeN, Apr 25, 2006.

  1. Ok well I want to start my first post off by saying how much I've enjoyed this site. I would have never even known where to start if it wasn't for you guys. This is my first post...and I'm dedicating it to my first grow.

    My first questions involve the cabinet. It's going to be somewhat stealth with dimensions of 50"H x 48 "W x 20"D. I'm running a switchable 400 watter and have both the MH and HPS bulbs already. These are running under a Hydrofarm Air-Cooled hood with a 6" flange that will be down-converted to the 4" inlet on a 465 CFM centrifugal blower. I know the blower is probably WAY bigger than what I need, but will I see any problems with using a fan this big? Even though it's hooked directly to the hood, will it still pull enough air from the rest of the box to ensure adequate ventilation?

    Just for fun, what kind of yields should I expect once I get a little better at this? :)

    I'm also wondering about the intake. I got the idea to go with (2) 2"x10" intake grills (like the kind you see on ceilings or floors for the AC). I was thinking about running a simple filter on each to prevent dust, bugs, etc. from coming in the intake. Are two 2"x10" inlets enough? Will the filters restrict flow too much? I decided on these grills because I need something relatively low-profile so I can push it up close to the wall.

    When I was buying some of the equipment, the guy at the hydro store acted like PH and TDS in soil grows wasn't all that big of a deal. He acted like PH and TDS wouldn't fluctuate enough to even worry about it. Is he full of it? I went ahead and bought a nice little PH meter, but should I pick up a TDS meter as well?

    I'm sure I'll have more questions as the grow comes along, and I appreciate any help you guys can give.
  2. Hey KeenofGreen,
    Welcome to Grass City. Your plan sounds awesome. I don't think you can ever have too much exhaust. More is much better than not enough. I think the hydro guy is right; PH does not fluctuate as much in soil as it does in hydro but, you made the right move by getting a ph tester. I have grown for years without having a TDS meter so, I think you will be fine for now without it. You can always buy it later if you find you need it. On yield I think you can expect (once you have grown a while) at least an ounce per plant depending on pot size. Feel free to ask more questions. Good luck and looking forward to seeing how the grow turns out.
  3. Thanks for the reply VTEC. This is really starting to get fun. :)

    My babies have been out of the ground for about 3-4 days now. How long should I wait before getting them under the MH? And when I do, how far should I keep them from the glass on my hood?

    The other thing I was wondering about was training methods. I had 11 seeds and all 11 germinated and are out of the ground now. Can I realistically hope for 3-4 females assuming they're taken care of and do I even have room for that many? What training methods should I try considering this is my first grow...and do they even need to be trained?

    I'll try and get my camera working and get some pics together. :)
  4. well bro looks like your off on a good foot.. I think you have a great chance of about 5-6 being female.. we'll see though eh? I would definitely have them under your hid lamp right now just put them about 2-3 ft away.. and put them about 5-6 inches closer every day til they are about 12" away , air cooled hood? if not about 16" maybe 2 ft depending on how hot you got it in there.
    The only thing about those grills that you used for the vents is that when your dark period is going in the closet those vents will let light it.. you almost need a damper on a timer to close when the lights go off.. if not you can make the intake be a piece of duct that curves around as to not let light in there.. but we all know, light leaks = herm's = no sensimilla for you.. and you want bomb herbs.. so do it right..

    the PH meter is all you need.. the plants will tell you about the TDS.. at least that is how I do it.. if they need more.. You'll know about it.. and if they need less you'll also know about it.. :)

    And your Yield question.. I'd say your first yeild ought to be a half a pound at least.. if you do good 3/4 of a pound.. around 10-12 ounces this time around... then again I've been doing hydro for about 2 years and don't do any dirt.. so if your doing dirt I'd cut the yeilds that I put up here in half .. either way you'll do good.. just take good care.. :)
  5. sounds like a sweet setup you got plans on there,,,your deminsions sound close to the size of a refrigirator,,,,, ive seen some setups on the net,,,, that was a straight up looking refrig. until the door was opened,,,,,, just a thought...good luck..:p

  6. irieluv took care of you ratio and lighting question, here is your training question. For your first grow I would NOT recommend doing any training, topping, pruning or any "advanced technique" Your first grow and maybe even second grow is to learn and get familiar with the plant and how to make it grow. In fact, it is really not even completely necessary to do any of those aforementioned techniques at all. Some growers get tons of bud just growing the plant straight up.

    As for yield I would not worry about that. Like you said, you are having lots of fun. That is most important not amount yielded. For a beginner growing in soil, it greatly depends on the size of the pot and how big you let the plant get before flower (amongst other things) but, be happy if you get 1/2 ounce-1 ounce per plant.
  7. Thanks a lot for all the help guys. I did finally finish the box last night and got them under the HID. Everything looks to be working pretty well except my temp gauge is showing a max of 88 degrees w/ around 35-50% humidity. It seems to be averaging around 82-84, but I'd still like to bring those down a bit. They should get better when I move the box into its final location, but I was wondering is one exhaust fan for just the hood enough to vent the entire box? Should I have a secondary exhaust fan for the actual compartment itself? Also, what part of the box should I leave the temp sensor on...or does it even matter really?

    Edit: I was just it possible to make an intake that's too large?

    I'll try and get some pics together within the next couple of days. I'm pretty pleased with how the box turned out and maybe with some pics you guys could critique it more. :)

    Thanks again for the help. :smoke:
  8. You cannot make the intake too large.
    As long as you build a labyrinth to keep the light out.
    That 465 CFM rating is rated in the ultimate environment.
    Meaning no push/pull air friction by being inside a box.

    If you have an airtight box with your fan blowing out air movement is around 0 CFM.
    If you drill a little hole 1/4 inch wide in there it may be a little bit better like 1 CFM.
    If you make a 1' by 1' hole in the box you may get close too 465 CFM.
    Be sure to make that on the opposite side of the box, preferably at the bottom if the exhaust fan is at the top (or the other way around like I have : top left intake fan, bottom right exhaust fan).

    Find yourself a small straw for drinking sodas.
    Make sure you breath only through the straw and then go run up and down the stairs a few times.:D

    Then, you will know what I mean with push/pull air friction really quick and understand a bit more about how big that intake hole should be.
  9. I figured the intake was ok. Just wanted to make sure. :)

    I found out I was having problems with the AC unit and now the temps in my box have gone down significantly. Temps are staying between 75 and 78 degrees with humidity around 35-45%. Is this ideal? And where should I be taking measurements exactly?
  10. Well here's an update...sort of...and not exactly the kind of update I wanted to have to post.

    The seeds have been in the ground since the 20th of April...and everything was looking OK until just recently. A couple of the seedlings aren't looking all that great and I'm not quite sure what the problem might be. Most of them have become slightly yellow. Some of them are even starting to droop a little and one in particular has started curling inwards pretty badly. Some of the stems aren't growing straight up either...and they are only about 1ft to 1.5ft away from a 400 watt MH.

    Temps are right around 75-80F w/ 28-35% humidity. The low humidity has me worried that spider mites or some other type of pest could already be attacking my plants. Is this possible?

    I'm also a little unsure about watering. I waited about 5-7 days after putting the seeds into the soil to water again, and only 2 days later the soil seems pretty dry. I have a moisture meter but how far down in the soil should I be checking it? Does the drooping leaves sound like a watering problem?

    I finally find my camera as promised...but now I can't find the USB cable so I can't post any pics just yet. Any help is greatly appreciated. :smoking:

  11. so you cant have a air tight box? or can u have it air tight and have intake and exhast fans? kind of confuzed on your statement.....

  12. Seedlings are pretty young to be nute deficient and shoul'dnt need to be fed yet. What type of soil are you using and does it have nutes in it? Drooping is usually from over or underwatering. Temp and humidity is fine. Do you see any pests in the soil or under the leaves? Usually spider mites are visible but, sort of hard to see. Examine her with a magnifying glass.
  13. Yo... p/ plant some is a bit invalid. In total, no matter how many plants you grow you should be getting around 6-8 ounces. You have a 400 watt HPS and on average you can expect .5g per watt. Therefore 200g divided by 28 grams per ounce is equal to a little oer 7 ounces. So when you get some experience I bet you could pull half a pound.
  14. OOPS. You got me there.:eek:
    I meant an airtight box with 1 hole in for that fan pushing air out. (which it cant because it cannot suck anything in)

    It is theoretically possible to make an airtight grow box as long as it can passively cool itself.

    Meaning has to be bigger then you want or its has to have cooling ribs on it and made out of material that doesnt insulate very well.
    Maybe someone can make a growbox out of a nice metal safe. One with 100.000 CPU cooling blocks attached to it to enhance its surface.
  15. my vegging box is airtight - kinda. The intake and exhaust ports have louvers that open when the fans come on. The reason for this is because I am running a CO2 system with it. My bulb is cooled in a closed system. This means that the intake air for my bulb comes from outside by cab and the exhaust for my bulb goes outside. The air around my bulb and the air in my cab don't mix (until outside of the cab, I guess :) )

    I have an atmospheric controller that I use (THIS ONE) to exhaust the box when the temp or humidity gets too high. When either the temp or humidity reaches the threshold, my controller automatically stops the release of CO2 and turns on my intake and exhaust fans. The movement of air from the fans opens the louvers and allows good air exchange.

    Once temp is about 6-8 degrees below my max, it shuts them off and restarts the flow of CO2. Same goes for humidity. This way, I'm not wasting CO2 and my plants get more of it. The controller also has a photocell in it that shuts off CO2 whenever the lights are off (again, so it's not wasted). Pretty slick little operation for the money. That controller is well under $200.
  16. Looks like you got yourself a pretty nifty setup dude! Thats like a 4 out of 5 star grow box you got there.:hello: :hello: :hello:

    I'm just wondering though, can you still adjust the light of the bulb with this closed system?

    Is it like a glass-tube (with the bulb inside it) connected to flexible air pipes with fans on both ends?

    Could you post us a picture maybe? I'd like to see your handywork.

  17. just one fan does the job on the tube. The tube is hung from a light hanger. They come pre-wired with a mogul. I bought it from by buddy CLICK HERE <-- if you look at that picture, just think of it in my cab hangin in a left to right orientation. I have a flexible duct on the front of that that connects to the side of my box and is the intake. There is another flexible duct that goes to the top corner of the other side of the box and then up through the top where it is connected to a Vortex fan. The Vortex runs whenever the light is lit and keeps it cool. (yes, the bulb is inside the glass tube).

    The little hangers you see in the pic are attached to a light raising/lowering device and I can move my tube up and down whenever needed. The really cool (pardon the pun) thing about it is that it lets you get that light a lot closer to your canopy than a normal reflector would. You can also mount them vertically if you had a bunch of plants growing in a room.

    So, whever my light comes on, so does the cooling fan. This keeps the box temps down so I don't have to vent as often and my CO2 gets to hang out with my plants more. When the box finally gets up to max temp, my controller turns on another fan and turns off the CO2. All the hot air is exchanged with nice fresh air and the controller turns off the venting fan and turns the CO2 back on.

    Absolute simplicity.
  18. I understand now.
    You are probably not doing your first grow I think:) .

    Looks like you are WAAAY ahead of me.
  19. No, I'm not. Not by a long shot:D

    But, if eveyone built one of these for their first grow, I would bet we would be seing a lot better results a lot faster.

    Do I get killer yields, sure. But I can't take all the credit for them. Look at the technology I'm using. All that stuff makes my grow almost maintenance free. Seriously, it would almost be a total afterthought to go check on it, if not for my daily excitement of wanting to see the plants and how much they are growing (I hope that never goes away :) )
  20. How many cfm does your vortex fan put out? I've got a cold fusion hood with 6" ducts going in and out of it but I think my fan is too small to keep the 400 watt bulb cool because the glass is very hot and my cabinet is getting up over 95 degrees even though my room temp is only 78-80. If I'm going to get a new one I want to try and get the smallest fan that can still do the job so I can try and keep noise and power consumption to a minimum.


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