# will this get too hot? tent set up help



## 707NewGenGrower (Aug 30, 2011)

im buying gear for 4x4 tent grow - this is what im thinking the set up will be
1000w hps in magnum xxl hood, 1 4'' vortex air cooling hood, another 4'' for exhaust, and smaller fan for intake (on timer alternating with co2) 
doing sog so im pretty worried about high heat when they small - does anyone have any experience with this set up? think it will stay under 80?


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## Hushpuppy (Aug 30, 2011)

If you are going with a 1000w hps hood, you should probably go with a 6" vent and fan for cooling it. I don't think that the Magnums come with 4" vent flanges, so you would have to go with 6" or get a reducer. If it was 400w or 600w even, you could get away with 4" vent but I believe with the 1Kw you have to have the 6" or you will fight heat. 

You will not need a fan on the intake for the tent. You should leave that passive and just use an exaust fan to pull air out of the tent. That will prevent any positive pressurizing of the tent which would lead to smell leaks, and its really not needed for that size tent. 

I assume since you are concerned about high heat when thay are small, you are intending to use just the HPS for lighting through veg and flower? I would recommend that you get you either some T5HO flourescent fixtures (maybe 2 4 bulb fixtures to hang on either side of the Magnum) or get a digital ballast that can run both MH and HPS and can be turned down to 600w, and run the MH bulb while in veg, then switch when you go to flower. That is what I do and it works quite well. The Lumatek digital ballasts are really nice.


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## Locked (Aug 30, 2011)

This will be my second year running a 4x4 tent....I run a 600w in a cool tube and a 400w in a standard reflector. I run one 6 inch inline fan rated at about 450cfm I believe. Hush is right about the intake...leave it passive. My tent has 3 passive intakes along the floor. The fan does all the hard work...pulling the hot old air from the tent via the cool tube and venting that air out a window. I don't even run a filter most grows. The negative pressure keeps the odor at bay. I runa small fan inside the tent down low just to keep dead pockets of air from forming as I will be the first to admit I fill my tent with ladies.


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## The Hemp Goddess (Aug 30, 2011)

CO2?  Tell us about that.


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## 707NewGenGrower (Aug 30, 2011)

i was going to use reducer but im thinking other wise now, im getting the picture that 1k needs 6'' or else too hot, what about 2 600's with 4'' for each?
i have t5's and ive used before but it doesnt compare to the lumens from 600 or 1000 at optimal temps and humidity, 
THG - i have my intake and my co2 reg on 2 sep timers, one is on for 30 mins while other is off and switches, co2 floods room for 30 mins then other timers kicks in and replaces stale air in room, osc fan always on inside


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## Hushpuppy (Aug 30, 2011)

The 600-1000w is great for lumens in flower but during the first ~6 weeks there is no need for the extra lumens, cost, or heat. That is why a lot of us run the T5s. How big is your CO2 bottle, and how long does it last? I have been looking at adding CO2 at some point. I saw some 20oz bottles at the Lowes for like 25-30 bucks. They are for tool and welding use so I would think they would raise fewer questions,IDK how long they would last for a smallish grow space though


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## buddogmutt (Aug 31, 2011)

the 1000w hps will only give you issues in the summer months..it gets hot in your area...feel me...but the rest of the year you'll be fine...600w would be plenty though...figure 100w per sqft...good luck...i have a 5x5x7 tent with a 1000w...with great ventilation and circulation so....it all depends on your final set-up and remember pics always help...good luck


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## Lemon Jack (Aug 31, 2011)

buddogmutt said:
			
		

> the 1000w hps will only give you issues in the summer months..it gets hot in your area...feel me...but the rest of the year you'll be fine...600w would be plenty though...figure 100w per sqft...good luck...i have a 5x5x7 tent with a 1000w...with great ventilation and circulation so....it all depends on your final set-up and remember pics always help...good luck




100 watt per square foot??  In a 5x5 tent you have twenty five square feet.
I think it easier to go by lumens per square foot 3000 for veg 5000 for flower should be your minimums.

And ya if I was going with the 1000 I would definitley go with the six inch.


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## The Hemp Goddess (Aug 31, 2011)

707NewGenGrower said:
			
		

> i was going to use reducer but im thinking other wise now, im getting the picture that 1k needs 6'' or else too hot, what about 2 600's with 4'' for each?
> i have t5's and ive used before but it doesnt compare to the lumens from 600 or 1000 at optimal temps and humidity,
> THG - i have my intake and my co2 reg on 2 sep timers, one is on for 30 mins while other is off and switches, co2 floods room for 30 mins then other timers kicks in and replaces stale air in room, osc fan always on inside



I have 2 600s with 4" duct connected to a 4 x 4 x 6 wye with a 6" Vortex fan.  It works great.  One 6" fan is going to be less money than 2 4" fans.  You will almost certainly need a speed controller, too.

While T5s do not compare with HPS, they do compare with MH and many here use them for vegging as they produce nice bushy plants with tight internodal spacing and a lot less heat. 

I do not run CO2, but....I don't think I have heard of anyone using it quite this way--flooding with CO2 for 30 minutes and then exhausting?  What concentration are you giving your girls?  Are you monitoring it?  How long does it take for the enhanced CO2 to be depleted?


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## The Hemp Goddess (Aug 31, 2011)

buddogmutt said:
			
		

> the 1000w hps will only give you issues in the summer months..it gets hot in your area...feel me...but the rest of the year you'll be fine...600w would be plenty though...figure 100w per sqft...good luck...i have a 5x5x7 tent with a 1000w...with great ventilation and circulation so....it all depends on your final set-up and remember pics always help...good luck



I'm confused here--If you needed 100w per sq ft, you should be running at least 2 1000w and a 400w as you have 25 sq ft.  If 707 was running 100w per sq ft, he would need 1600W, not 600W.  However, since lumens per watt varies so much between different types of light, we use lumens per sq ft rather than watts per sq ft to figure lighting needs.  As Lemon Jack mentioned 3000 lumens per sq ft for vegging and 5000 lumens per sq ft for flowering.  These are minimums.

Also, ventilation is for more than heat control--your plants need a continual supply of fresh air all the time the lights are on for proper photosynthesis.  I run 2 600w in a space 3 x 6.5 (19.5 sq ft) and I have heat issues all the time, even in winter when it is quite cold.


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## 707NewGenGrower (Aug 31, 2011)

my tank is 15 lbs. long story short this is the smallest tank you can get away with in a 4x4, i have to fill it up once a month, but co2 ppm is always 1500-1800
if you dont use co2, i HIGHLY advise spending the extra few hundred bucks and get tank (prefer 20-25 so u dont have to refill as much) get reg, and timer
will increase yield dramatically, decreases cycle time because more co2 more it can photosynthesize, very dense nugs, and lots lots more THC in end
if you google it you'll find reasearch saying that the plant can tollerate up to 95 deg with co2. my first run ever my temps were 90-92 every day, but i flooded with co2 and there was no burn and they turned out great, not to mention alot more weight then i expected. which is why i believe is high heat high co2 method
so i like the idea of 2 600's in tent THG, the only thing is i already have 2 4'' fans, i would have to buy a 6'', which isnt a huge deal but if i can get away with using the 4's id like to. but what do you do, daisy the 6's together, 6'' for exhaust and passsive intake with osc inside?


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## 707NewGenGrower (Aug 31, 2011)

Hushpup - call brewing companies or bottling places they have tanks they cant use and will sell for cheap because they used but lightly, or craigslist


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## buddogmutt (Aug 31, 2011)

i was medicated..lol...math was off on that 1.(100wper ft...not sqft..my bad) ..the rest of the info is correct though....thats why agreed a 600w would be enough for a 4x4...and you gotta take into account the climate in his area...he's like me..95-101-102 is very common in our ares in the summer...im talkin 80 at midnight....3months of hot heat...


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## Sol (Aug 31, 2011)

707NewGenGrower said:
			
		

> Hushpup - call brewing companies or bottling places they have tanks they cant use and will sell for cheap because they used but lightly, or craigslist



  Since you seem to exp. with co2, what do you think of the yeast,sugar,baking soda method for a small small space? Or is it a waste of time? I mean besides the regulation issue, is it a waste of time besides that? I use a bubbler stopper at the top like the wine casks use to bleed off co2, but i'm not sure if its worth the aggrivation or should i also take your advice and get a tank and do it proper?  BTW i read the same info on heat tolerance with co2 and want to take advantage of that technique.


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## pcduck (Aug 31, 2011)

I am with THG, I do not understand your method of co2 enrichment.

Wouldn't turning on the exhaust fan just deplete the co2 that you just pumped in? If I was not gonna to monitor the rate of co2 usage I would at least give the co2 a change to get used by the plants before turning exhaust fans on. Just my $0.02


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## 707NewGenGrower (Aug 31, 2011)

solanero - waste of time in my opinion unless its a huge container, its not going to produce enough co2 to keep it at cponstant 1500-1800 ppm 
if u have a small space, get a sealed container, put whole in top, attach tubing, put on back of osc fan, and put dry ice in container. have to look up exact cubic feet 1 lb covers, but i always bought around 1/2-3/4 lb of dry ice per day

pcduck - if the fan is on the top of the tent it is only sucking hot air up, co2 is heavier than air so it stays on bottom of tent, at the rate its replacing the air its not fast enough to suck out the co2 the rate its going in


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## The Hemp Goddess (Sep 1, 2011)

Solanero said:
			
		

> Since you seem to exp. with co2, what do you think of the yeast,sugar,baking soda method for a small small space? Or is it a waste of time? I mean besides the regulation issue, is it a waste of time besides that? I use a bubbler stopper at the top like the wine casks use to bleed off co2, but i'm not sure if its worth the aggrivation or should i also take your advice and get a tank and do it proper?  BTW i read the same info on heat tolerance with co2 and want to take advantage of that technique.



It is a waste of time, money, and energy.  You cannot get the CO2 levels high enough to really be of benefit.  If you cannot control and monitor your CO2, it is a waste.  IMO, in a small space, exchanging your air 3-4 times a minute gives you plenty of CO2.  Get your space really dialed in before attempting CO2 enhancement--there is a lot more to it than simply letting CO2 go in the room.  One of the things needed to take advantage of extra CO2 is enhanced lumens, an air tight space, coordinated exhaustm, etc, etc...


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## The Hemp Goddess (Sep 1, 2011)

707--I have to disagree with your analysis of how this is working--the air WILL get mixed by the action of the exhaust fan pulling and the CO2 does not stay on the bottom of the room.  And unless you are pushing over 200 cfm of CO2 into the room, it is being exhausted out....An HVAC person might be better at explaining things here....


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## 707NewGenGrower (Sep 1, 2011)

as i said this is what i have always done, and it has worked great
unless you have tried or even experiment with co2 its hard to make judgments about the results
i did NOT invent this method, it is a technique that has been perfected by many and i was taught it, disagree or agree im sharing experience


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## The Hemp Goddess (Sep 1, 2011)

Thanks, I appreciate you sharing.  I am kind of a science kind of gal--I kind of need to be able to work things out in my head....I'll continue to think on how this could work.


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## Locked (Sep 1, 2011)

Wasn't there a grower on here who was considering running Methane in their tent?   Wonder if they blew themselves up....


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## 707NewGenGrower (Sep 2, 2011)

so i looked more into the method called some friends that do it
its called "closed loop" method as opposed to "open loop" 
the amount of difference you see with high co2 is just amazing, if you ever get a chance thg to try dry ice, or co2 tank or burners i highly recommend it
heres some hard info on it hope it helps

There are two different ways to set up a grow room. Open loop or closed loop, also known as a sealed room. An open loop system has open ventilation, or a fan pushing air into the room and another fan exhausting air out of the room. This is known as ventilation or air exchange. It is exactly what it says; exchanging the old air in the room with fresh, cool CO2 enriched air. In a normal grow room you need to exchange the air at least once every one to two minutes at minimum. Personally, I like to exchange the air about once a minute up to every 30 seconds. Some say thats not necessary but the more air exchange the better in an open loop room. The air exchange is controlling three different elements in the grow room. It is controlling the air temperature, the CO2 levels in the room, and the air quality. As the fresh air is delivered to the room it brings cooler temperatures, flushing out the hot air in the room and replacing it with fresh CO2 enriched air. The fresh air exchange for air quality and CO2 replenishment is one of the most critical factors in a successful grow room.
If your room is completely sealed (closed loop), and the vents bringing in and exhausting air have filters on them, the chances of bugs and diseases getting into the room are greatly lessened. As long as you dont bring in any dirty or infected plants into the room, and dont transport something in from outside on your clothing as you enter the room then you will have a bug and disease free grow room.
Compared to an open loop room, a sealed or closed loop system has no fresh air intake and no main exhaust. The only air running into the room is for cooling the lights, removing the heat from the room. Since the fan is connected by ducting to an outside fresh air source such as a window or adjacent room, the air never comes in contact with the room air, as long as you use proper air cooling lights with a sealed glass lens. The air is simply brought in through the ducting (always pushed, never pulled through the lights) and pushes the hot air out of the lights through further ducting, normally up into the attic as heat rises. A simple charcoal filter, with an inline fan for scrubbing and recalculating the air, is also needed to accomplish this properly. The filter or scrubber in this case is running through the room, constantly cleaning the air free of molds, fungi and diseases


A plant must have the proper CO2 levels in the air to be a healthy plant, with a healthy immune system, which will fight off molds, diseases and bugs, and produce healthy bountiful fruit. Outside, the air we breathe has about 400-450 ppm (parts per million) of CO2 all the time. For plants, this is a happy level of CO2. However at levels around 200 ppm, a plant can actually start choking or suffocating. At levels this low the plant will not be healthy and may even die. Plants can use levels of CO2 up to 2000 ppm 4-5 times that of normal ambient levels, and achieve optimal growth and production. Performance can be enhanced by adding CO2 to the room, increasing the levels significantly. This can only be done efficiently in a sealed or closed room. This is why air exchange in the room must be happening constantly, ensuring the CO2 does not drop below ambient.
In an open loop system, supplementing with CO2 is a bit wasteful since the fans are constantly exchanging air in the room, bringing it back to ambient CO2 levels in just minutes. 
Compared to an open loop room, a sealed or closed loop system has no fresh air intake and no main exhaust. The only air running into the room is for cooling the lights, removing the heat from the room. Since the fan is connected by ducting to an outside fresh air source such as a window or adjacent room, the air never comes in contact with the room air, as long as you use proper air cooling lights with a sealed glass lens. The air is simply brought in through the ducting (always pushed, never pulled through the lights) and pushes the hot air out of the lights through further ducting, normally up into the attic as heat rises.
A simple charcoal filter, with an inline fan for scrubbing and recalculating the air, is also needed to accomplish this properly. The filter or scrubber in this case is running through the room, constantly cleaning the air free of molds, fungi and diseases.
Finally you have the CO2, But instead of being at roughly 450 ppm of CO2 in the air as in an open loop room, we can increase the levels up to 1500-2000 ppm. By doing this we can enhance the plants metabolism rate and its growth and flowering will be dramatically enhanced.


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## 707NewGenGrower (Sep 2, 2011)

methane? why??? hahaha


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## The Hemp Goddess (Sep 2, 2011)

I tried dry ice, yeast and water, etc, etc, years and years ago before we know that CO2 enhancement needs to be controlled and regulated--if you have grown long enough, you have tried everything.  I know that DIY systems that do not control or regulate the amount of CO2 are pretty much a waste of time, money, and effort.

I understand the closed loop and the need for a sealed room--part of why I do not run CO2.  However, this is not what you said you had or used--you indicated that you personally were putting CO2 into the room and exhausting the room out 30 minutes later--not a closed loop.  That is what I could not understand--how the plants benefited from only 30 minutes of CO2 and then exhausting everything to the outside?


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## 707NewGenGrower (Sep 6, 2011)

what im doing is a combo between closed and open, i cannot do full closed loop because of temps, so i do half closed (turning off exhasut so co2 is not wasted) then timer switches to open, replaces air cools temps then co2 kicks in again
having it on timer, also ensures my ppm gets too high which eliminates need for controllers
having co2 dripping 6 hours of 12 will be much better than not


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## Hushpuppy (Sep 6, 2011)

I am with THG on this. I can't see how having only 30 minutes of CO2 injection before having it sucked out would benefit the plants anymore than just having the air being pulled in from outside constantly. I could be entirely wrong on this but, if you flood the room with 1500-2000ppm of CO2 it should take longer than 30 minutes for the plants to be able to utilize it. I would think that your system would work better if you flooded with CO2 for 30min, let sit idle for 1-2hours then flush with fresh air for 30min, then repeat. 

Again, I may be wrong but I think the enhancement of your grow is just coming from having a good flow of fresh air that is somewhat supplimented with extra CO2.


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## HomeTNGrown (Sep 8, 2011)

707NewGenGrower said:
			
		

> im buying gear for 4x4 tent grow - this is what im thinking the set up will be
> 1000w hps in magnum xxl hood, 1 4'' vortex air cooling hood, another 4'' for exhaust, and smaller fan for intake (on timer alternating with co2)
> doing sog so im pretty worried about high heat when they small - does anyone have any experience with this set up? think it will stay under 80?



I would run a 1k  in a 6x6 tent with a flood drain table that was 4x4. in a 4x4 tent i run a 600 watt hps and vent it out with 2 fans from the intake/outtake and i kept it around 80 to 85, I dont use co2 haven't seen it do much of anything when i use it expet for reflling it, but others will swear by it, I would say use the co2 if it was going to get over 85 hope this helps!


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## rickyjack9 (Mar 15, 2014)

lots of fan experts out there.
a cheap fan on I/p actually does help a little.
I am also a believer in speed controller. on my 6" 460 cfm o/p fan.
I also dropped 10 degrees with I/p fans from home depot. 120 cfm each.
I have 2  6" I/p ducts.


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## Growdude (Mar 17, 2014)

Without a ppm controller your just guessing at the levels your at.
Here is a calculator hxxp://www.hydroponics.net/learn/co2_calculator.asp.

You never said what CFM your set at, (need a flow meter, not just a regulator), but at 1CFM your on time should be about 8 min.

In my tent I use motorized dampers that divert my fan from pulling thru my light to exhausting the tent. these are controlled by the C02 controller and temp/humidity controller.


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