Tips for a new grower

[MrOctave]

Hello guys,

Just recently got my hands on a set-up and was hoping to ask a few questions that would be crucial to my grow.
I have got my 600 watt HPS set-up but its a small grow room "80x80x140cm".
Problem is i cannot fit a grow tent in there and i cannot put a extraction fan in there.
I was only planning of putting 4 plants in there, what would happen if i do not have a extraction fan to remove the hot air?
and would a 600 watt bulb be to much?

Any help would be amazing, and sorry for bad grammar

 

[Weaselcracker]

A 600 watt bulb is a bit overkill for the space- but that's ok- they done mind 'extra' light.
The problem is the heat. You'll need ventilation no matter what- but a 600w hps needs a real vent fan setup.
All lights make heat. LEDs and cfls make somewhat less.
Four plants will pretty much fill that space by the time they are flowering, depending on the strain and whatnot.

 

[MrOctave]

A 600 watt bulb is a bit overkill for the space- but that's ok- they done mind 'extra' light.
The problem is the heat. You'll need ventilation no matter what- but a 600w hps needs a real vent fan setup.
All lights make heat. LEDs and cfls make somewhat less.
Four plants will pretty much fill that space by the time they are flowering, depending on the strain and whatnot.

I wouldn't be able to put a extractor in their, but would I be able to get away with multiple fans to keep the temps down?. and maybe leave the door slightly open to let air in.

 

[Budley Dorite]

As Doc Bud says: "Environment is KING" You'll need to have "control" of temps & humidity for best results.

 

[Weaselcracker]

Plants need fresh air, just like people. The other reason for bringing in fresh air is for cooling purposes. So leaving the door open is a start but I doubt it would be enough to cool down the room much.
Having fans inside the room, like desk fans I think you mean, blowing air around, won't do much to cool the room. They would just help circulate it within the room and even it out a bit. You need a source of cooler air to bring the temps down.
If you are using a low wattage light source, like a few cfl bulbs or a very small led, and one or two small plants, I'm guessing you could be ok for heat with just the door open. It's necessary for the plants to have a regular schedule of darkness during flowering though- so you'd probably have to close the door every night at a set time.


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[MrOctave]

Well, Im not going to be able to get "best results" which is a shame. But would i be at least able to grow the plant and get some yield without a extractor and just with 2 basic fans and leaving the door slightly open for vent?
Or will i end up killing the plant

 

[Weaselcracker]

Yes if you use low wattage/low heat lighting. I can't say for sure how hot you'll get in there with a 600 watt light- but I think it's a pretty safe bet that it will be too hot for plants. Above 90 degrees celcius and plants start to have serious issues which make it hard for them to grow.
If you already have this 600 watt light you're talking aboutt- plug it in and check the temps.
But- If you can have the door open, and have regular fans inside the room, why couldn't you just replace one of those regular fans with a vent fan- blowing air out of the room?

 

[MrOctave]

Yes if you use low wattage/low heat lighting. I can't say for sure how hot you'll get in there with. 600 watt light- but I think it's a pretty safe bet that it will be too hot.
But- If you can have the door open, and have regular fans inside the room, why couldn't you just replace one of those regular fans with a vent fan- blowing air out of the room?

Can you suggest any cheap vent fans or a link to a good purchase. I dont have alot of spare cash but if i can get one cheap then I may just get one. Also if i bring the bulb down to a 400watt HPS would that be better then ?
And thank you for you help so far

 

[Weaselcracker]

I don't know of any particular special deals on vent fans. I'm pretty sure that any of the top of the line fans will do the job equally well. It will vary depending what country you're in as well. There are many threads on this subject in the forum, and I'm going to be looking soon, as I want to replace my vent fans with better, quieter ones.
For a light- you can get a switchable/dimmable ballast. I have several. They switch between 300-400-600 watts, and take both MH and HPS bulbs.

 

[Major PITA]

More light is needed in bloom. That's when you'll probably have the most heat problems. Leaving the door open sounds bad as you could easily mess up the light cycle. I guess with autos it might be OK.

Why can't you add an exhaust fan?

 

[MrOctave]

More light is needed in bloom. That's when you'll probably have the most heat problems. Leaving the door open sounds bad as you could easily mess up the light cycle. I guess with autos it might be OK.

Why can't you add an exhaust fan?

If i can find a cheap extraction fan or some examples, (Im completely clueless about extraction), then i will probably try and get on. I just really need some help on the whole extraction fan stuff

 

[Weaselcracker]

Check that link I gave you a few posts back.

 

[Major PITA]

Since your space is only about 32 cu-ft., you can go with a small, inexpensive fan. The cheap, inline duct "booster" fans are way overrated as to what they actually can do, but in your case, one should do the trick.

IDK what "cheap" is to you, but these are readily available for $15 - $30. Suncourt is a common brand around here. If you can duct cool (outside?) air into the space, it will make the fan much more effective at reducing temp's than pulling 75 degree room air through the grow.

 

[TanR]

Hi MrOctave.

Welcome to the 420 Magazine community of members.

I have run a 600 watt light in a tent using only a couple small desk fans and leaving the tent flap open. When I first started growing, I just didn't want to run out and spend a ton of money right off, so I made do with as many "around the house/repurposed" items as I could. I had two desk fans suspended from the top of the tent. One blowing fresh air in, and one blowing from inside the tent toward the flap. Temperatures in the tent did get a little warmer than ideal once or twice, but did no harm to the plants overall.

I found that due to the warmer than ideal temperatures, I had to water a little more frequently than I have in subsequent grows with an extractor fan but other that, not much of a challenge really.

I like to think of all the different environments this plant grows in naturally and this leads me to think that surely there are many places around the globe where the temperatures get a little warmer than "ideal" and the plants do just fine.

Be well and happy growing!

 

[MrOctave]

Hi MrOctave.

Welcome to the 420 Magazine community of members.

I have run a 600 watt light in a tent using only a couple small desk fans and leaving the tent flap open. When I first started growing, I just didn't want to run out and spend a ton of money right off, so I made do with as many "around the house/repurposed" items as I could. I had two desk fans suspended from the top of the tent. One blowing fresh air in, and one blowing from inside the tent toward the flap. Temperatures in the tent did get a little warmer than ideal once or twice, but did no harm to the plants overall.

I found that due to the warmer than ideal temperatures, I had to water a little more frequently than I have in subsequent grows with an extractor fan but other that, not much of a challenge really.

I like to think of all the different environments this plant grows in naturally and this leads me to think that surely there are many places around the globe where the temperatures get a little warmer than "ideal" and the plants do just fine.

Be well and happy growing!

Thank you for your help, im not using a grow tent but a 80x80x140 ish closet under the stairs (some random wider parts) its a wierd shape but do you think if i cut a hole in the door of the closet and place a vent pipe through it with a fan that would work just fine?

 

[Major PITA]

Thank you for your help, im not using a grow tent but a 80x80x140 ish closet under the stairs (some random wider parts) its a wierd shape but do you think if i cut a hole in the door of the closet and place a vent pipe through it with a fan that would work just fine?

If you pull warm-ish air through, it will take quite a bit more to cool the space. At least your plants will be getting fresh air. Anything is better than nothing. If your HPS has a cool tube, it will help even more if you can connect it.

 

[TanR]

MrOctave,

As usual, Weaselcracker and PITA's suggestions/advice are spot on and I'm not trying to contridict them in any way. However, you did mention in an earlier post leaving the door open some and I therefore related my experience with a tent and open flap/door.

I would suggest, as I think others have, that it is going to take more air movement than you might imagine to keep your temperatures in check. As a test, you might go ahead and mount the light and run it for a day or two with no plants and monitor the enviroment. Experiment a little and determine how wide open you need to leave the door, whether a desk fan blowing in will prove adequate, etc...

My space had about 3 times the cubic ft. of yours and it took two 8 inch desk fans running on medium to high to keep the temps below the "way to hot" zone.

Be well and happy growing.

 

[Weaselcracker]

It sounds like TanR has made it work with the open door thing and real life experience is worth more than guesses any day.

An under stair closet will most likely be uninsulated. Bare walls. So rather than cut a hole in the door- I would cut it through a wall- more practical and much easier and cheaper to repair later on.

 

[MrOctave]

It sounds like TanR has made it work with the open door thing and real life experience is worth more than guesses any day.

An under stair closet will most likely be uninsulated. Bare walls. So rather than cut a hole in the door- I would cut it through a wall- more practical and much easier and cheaper to repair later on.

Lets just say i did have a under the stairs grow, and the temps were to high, would that kill all the plants?
Or would i still get a yield ?

 

[Weaselcracker]

It depends how high.
There are a lot of factors involved. So many that it's not really worth trying to pick it all apart and look at all the variables and different aspects. Here are some general guidelines.
Generally you don't want to have temps much higher than 85 Celsius, and 90 is considered by most people to be the absolute upper limit. That's temps at the top of the plant. The roots are happiest a little cooler. 75 degrees is the upper limit for them and 65-70 degrees is considered ideal for the roots. Water doesn't hold oxygen well when it gets above 70 degrees. Without oxygen the growth in the root zone slows quickly. All sorts of nasty root rot type pathogens thrive in low oxygen environments, while the beneficial bacteria and fungi that you need in there for healthy growth will die off.
Above 90 degrees, I am told, leaves begin to lose their ability to perform photosynthesis. So basically- they stop working well at higher temps. They also burn and get crispy.
According to Ed Rosenthal, famous cannabis growing expert, buds grown in higher temps have reduced thc.
Basically, if your temps are too high, your plants are going to suffer. They will be weaker and more likely to suffer various health problems. Yield will go down, and potency will drop.
On the other hand- you could skip all that and put in proper ventilation
Setting up a room and figuring out how to grow a bunch of plants in it- is a lot of work. It's only going to be more work when the basics aren't covered- never less.
Having said all that- there may be ways to cut a few corners. We all do it. Like you could try to vent the room by opening and closing the door instead of putting in a fan, etc. Personally I think that this particular idea would be ten times as much work as finding a way to put in a fan, but there may be other ways to improvise like that and cut some costs.
I don't think you can change the basic laws of nature though. Like- don't expect to run a room at 95 degrees and save time and money on a fan while producing worthwhile bud. It won't be worth it.