Thoughts on Grow Tents / Grow tent myths commonly found online

[vchaz]

Hello everyone, I'm a new member here and a newer farmer as well. I have been using grow tents for about a year. I currently run a 5x5 Apollo Horticulture tent as well as a 2.5 x 2 gorilla grow tent lite.

I will post some pictures here as well of my design / setup.

I have carbon filters, inline fans, regular fans, oscillating fans, dehumidifier and humidifier, Cree COB grow lights, some supplemental lights from RapidLED, as well as some flower initiators from GrowMau5.

At night I take in cool air from the outside, and in the day I typically push my warm air out into my apartment and draw in air from the outside if the outside is cool enough. If it's warm outside, I push my warm air outside and draw in cool air from my apartment.

Here is what I've learned about grow tents, which is contrary to a lot of the information you will find online and on youtube:


Light Leaks:
---------------------------
When the lights inside your grow tent are on, and the lights outside your grow tent are off, sometimes we will notice small amounts of light coming through the seams near the zippers and the zippers themselves. A lot of people see this and freak out thinking "LIGHT LEAK! MY PLANTS!!!!!".

While this does indicate that light is able to get out / come in through those seems, we have to evaluate whether or not this is going to be a concern. Let me explain why it might not be for most people: Inside of our grow tents, we have very high light intensity. Outside of our grow tents, we tent to have a lot less light intensity, otherwise we might not need to use a grow tent. While we may see the light peaking out of the tent when our room lights are off but our grow lights are on, try the reverse. Turn your grow lights off and then zip yourself up in your tent, leaving the lights in the room on. You will notice that there doesn't seem to be any light coming into the tent. Does this mean your tent doesnt have any light leaks? Of course not! You've seen them. What it means is that there is more light intensity/light pressure inside of the tent than outside of the tent. If the light intensity/light pressure outside of the tent is enough to penetrate the seams and zipper when the grow lights are off but the room lights are on, you should patch the tent. Otherwise, you really don't need to worry about light that leaks out but doesn't leak in. Most standard 45-60w bulbs that we have in our ceilings are not enough to penetrate the tent. If you have strong lights outside of your tent, perhaps because you don't veg your plants in a tent, then you may also run the risk of light coming into your tent. However, most people don't have that problem.


Air Pressure / Negative Pressue:
---------------------------
Most videos on youtube tell you that you want to have "negative pressure" inside your grow tent. Essentially, you want the walls of your tent to be sucked in when you have your inline fan running and moving air from inside of your tent to somewhere else, perhaps out a window or just into the same room. The fact is, you do not want negative pressure. Negative pressure means that air is leaving your tent faster than it is being replaced. If you have supplemental Co2 in your tent, you are likely wasting it and have very low PPMs. What you actually want, is positive pressure. You want to have so much air coming into your tent, that the sides are not caving in. I have accomplished this by hanging a very large fan, aiming it towards the lights, and turning it on full power when the lights are on. This essentially makes sure that I always have a balanced or slightly positive air pressure. If I were to turn my regular fan off, the air pressure would turn negative again. I will post a video of this as well.

Thats all the thoughts I have for now, I will be back with some pictures of my grow tent design and explanations of everything. Currently I have just a few really smallish plants in my tent, so I would consider changing my design a little bit if I was going for a full canopy. For instance, I have PVC pipe setup so that I can create a SCROG if I need to.

 

[MIMedGrower]

I agree with some of the above post but without negative pressure (tent or room) smell will escape.

Larger intake will minimize the tents walls sucking in. But some negative pressure is neccesary to operate a carbon filter.

Tents are not airtight so co2 would be wasted regardless. They are made for flow through ventilation.

 

[oldskol4evr]

well if you truely believe in your studies,roll with it,nothing goes as planned or designed,that you can take to the bank,this i know for a fact about your light theroy,i have a buddy that does nothing but outdoors,for the longest time he would reveg his plants couldnt figure it out,so i asked him how many hours of light you getting,he told me,and all seemed perfect until i seen the light pole in the neighbors yard,by the way were is your info from ?sounds like crackers to me,not bashing i want to see it done if you dig,i dont believe shit i read,proof is in eye sight

 

[oldskol4evr]

i also know for a fact because i did do it,the light theroy again,my timer had a red light on it,it was behind one of the plants i grew and i had some the best hermied seeds you ever seen,keep this in mind also animals have difrent eye lids to be able to see in the dark and protect from the sun,so you might throw that around also in the science project

 

[vchaz]

To be clear, I’m saying that not all light from outside of the tent makes it inside the tent. I’m not saying anything about indicator lights inside the tent, which are typically red and are strong enough to cause stress issues. But a lot of people are worried about light getting into their tent because they see it coming out of their tent, and that’s not always the case.

As for street lights, those will absolutely cause issues when growing outdoors considering most street lamps where I am from are HPS lights.

Also, I live in about an 800sqft apartment and I don’t have any issues with smell escaping, even when I have the tent wide open during flower smell doesn’t really escape. The only time smell escapes is if I turn my inline completely off. I’ll get a pic up tomorrow because the lights are out and I don’t feel like taking a picture, but during the day I open two of the side vents at the bottom, and I have fans outside of the tent blowing air in through those vents. Honestly, I can smoke in the other room of my apartment and the smell will never leave my apartment and will be gone within 10-20mins or so. I can watch the smoke loft over my head, go through the door and make its way into the tent.

 

[JWM2]

You can run co2 in a tent. However you’ll want it to be sealed and not ventilated otherwise you’re just wasting co2. You can vent at night when the lights are off. I’ve got a commercial buddy who does it like this and he’s had great success with it. I don’t run co2. I like plenty of fresh air flow. That being said it’s difficult to dial in your parameters in a tent due to all the leaks and outside air coming in through channels not regulated or conditioned. It takes trial and error and some inkbird controllers to help keep things dialed in.

 

[Mr Bee]

To be clear, I’m saying that not all light from outside of the tent makes it inside the tent. I’m not saying anything about indicator lights inside the tent, which are typically red and are strong enough to cause stress issues. But a lot of people are worried about light getting into their tent because they see it coming out of their tent, and that’s not always the case.

As for street lights, those will absolutely cause issues when growing outdoors considering most street lamps where I am from are HPS lights.

Also, I live in about an 800sqft apartment and I don’t have any issues with smell escaping, even when I have the tent wide open during flower smell doesn’t really escape. The only time smell escapes is if I turn my inline completely off. I’ll get a pic up tomorrow because the lights are out and I don’t feel like taking a picture, but during the day I open two of the side vents at the bottom, and I have fans outside of the tent blowing air in through those vents. Honestly, I can smoke in the other room of my apartment and the smell will never leave my apartment and will be gone within 10-20mins or so. I can watch the smoke loft over my head, go through the door and make its way into the tent.

I,v grown in tents for years and never had a light leak problem even though I can see wee bits o light coming out but the light on the inside of my tents are way more intense than any light on the outside so no light penetrates in.if it's something that really bothers you, you should buy a few meters of black out plastic and have it hanging over the place were the light leaks are and that should solve any problems in that regard.

 

[oldskol4evr]

To be clear, I’m saying that not all light from outside of the tent makes it inside the tent. I’m not saying anything about indicator lights inside the tent, which are typically red and are strong enough to cause stress issues. But a lot of people are worried about light getting into their tent because they see it coming out of their tent, and that’s not always the case.

As for street lights, those will absolutely cause issues when growing outdoors considering most street lamps where I am from are HPS lights.

Also, I live in about an 800sqft apartment and I don’t have any issues with smell escaping, even when I have the tent wide open during flower smell doesn’t really escape. The only time smell escapes is if I turn my inline completely off. I’ll get a pic up tomorrow because the lights are out and I don’t feel like taking a picture, but during the day I open two of the side vents at the bottom, and I have fans outside of the tent blowing air in through those vents. Honestly, I can smoke in the other room of my apartment and the smell will never leave my apartment and will be gone within 10-20mins or so. I can watch the smoke loft over my head, go through the door and make its way into the tent.

well im confused then,if you have no problems with smell and not concerned with lights,why not just black out the room windows and grow the whole room im saying,as far as light coming in around the door a sleeping bag stapled to the door frame take care of light,and pressure is ideal,hell use the whole room

 

[MIMedGrower]

To be clear, I’m saying that not all light from outside of the tent makes it inside the tent. I’m not saying anything about indicator lights inside the tent, which are typically red and are strong enough to cause stress issues. But a lot of people are worried about light getting into their tent because they see it coming out of their tent, and that’s not always the case.

As for street lights, those will absolutely cause issues when growing outdoors considering most street lamps where I am from are HPS lights.

Also, I live in about an 800sqft apartment and I don’t have any issues with smell escaping, even when I have the tent wide open during flower smell doesn’t really escape. The only time smell escapes is if I turn my inline completely off. I’ll get a pic up tomorrow because the lights are out and I don’t feel like taking a picture, but during the day I open two of the side vents at the bottom, and I have fans outside of the tent blowing air in through those vents. Honestly, I can smoke in the other room of my apartment and the smell will never leave my apartment and will be gone within 10-20mins or so. I can watch the smoke loft over my head, go through the door and make its way into the tent.

I would be willing to wager you think you cant smell it but others are already aware.

What you descibe would push the smell all around.

We get very used to the smell. To others it can be quite powerful.

 

[oldskol4evr]

I would be willing to wager you think you cant smell it but others are already aware.

What you descibe would push the smell all around.

We get very used to the smell. To others it can be quite powerful.

correct,you would be surprised how many heads ive been able to smell in a lumber yard,i cant smell it ,but when mama's nose does she lets me know haahah,crazy shit is im in a ilegal state as of now,did here last friday the passed a bill for under a oz is a mist,hell they just might get on board with the money train around these here parts hahahah

 

[Jimster]

I would be willing to wager you think you cant smell it but others are already aware.

What you descibe would push the smell all around.

We get very used to the smell. To others it can be quite powerful.

I have to agree with the Noseblind issue. There is almost always some odor, but with us growing and smoking, we tend to not notice it anymore, like salty food.Some folks get used to eating salty food, while others couldn't eat it because it was too salty for them. I have seen many small grows that vented outside, and during flowering, you would swear that a family of skunks lived in the area. Go away for a week to let your nose reset, and you will probably notice it then.

 

[Mr Bee]

I dunno how many times I,v been out and about and someone's came up to me and said "dude your totally stinkin o weed" and I,v had no clue I stank at all.

 

[vchaz]

Right, running co2 when the lights off is pointless because the plants aren’t photosynthesizing.

well im confused then,if you have no problems with smell and not concerned with lights,why not just black out the room windows and grow the whole room im saying,as far as light coming in around the door a sleeping bag stapled to the door frame take care of light,and pressure is ideal,hell use the whole room

Have you ever had a landlord before? Because I don’t trust mine lol. I live in a decent sized building but there are multiple reasons a landlord might enter my unit. For example, to fix something I’m not able to fix myself. Recently they were in my unit with government employees to conduct a tax assessment appeal. They also have permission to enter to show the unit within 60 days of me leaving, as well as being able to enter without notice in case of emergencies like a bursted pipe in the winter or something (which was common and happened in the unit below me this winter, I made sure to be the top floor unit).

 

[Jimster]

I dunno how many times I,v been out and about and someone's came up to me and said "dude your totally stinkin o weed" and I,v had no clue I stank at all.

One time about 15 years ago, I was sick and went to visit my Dr, who smoked. I walked into his office with a half an Oz of my buds in a small mason jar. I sat in the waiting room for about 5 minutes when he actually came out into the waiting room (I was the only patient there at the time) and told me to get that stinky shit out of the office, he could smell it in the back as soon as I walked in. I couldn't smell it, my wife didn't notice it, but the Dr said it smelled like skunk piss in the office and he told his staff thatmy dog was sprayed by a skunk and I got it on me. I never realized how much it can stink, especially Indica's!

 

[SoLowDolo]

Yea, I didn't realize how bad I reeked of weed the other day til I got into my car. It was horrible. Of course I had just got done trimming without gloves too so that didn't help lol.

I agree about the light leaks tho. I leave my lights on outside the tent all the time. You can see all kinds of light leak out but my little 12 watt CFLs aren't penetrating into the tent lol. I even have my gavita running outside my tent for the last few weeks without issues.

 

[Jimster]

Right, running co2 when the lights off is pointless because the plants aren’t photosynthesizing.

Plants do most of their growing during the dark periods, sort of a reverse process of what they do during the day. They take O2 in during dark periods, although not nearly as much as they make during lighted periods. I'm not certain what processes happen during the lights off, but they are actively growing 24/7.

 

[oldskol4evr]

Right, running co2 when the lights off is pointless because the plants aren’t photosynthesizing.



Have you ever had a landlord before? Because I don’t trust mine lol. I live in a decent sized building but there are multiple reasons a landlord might enter my unit. For example, to fix something I’m not able to fix myself. Recently they were in my unit with government employees to conduct a tax assessment appeal. They also have permission to enter to show the unit within 60 days of me leaving, as well as being able to enter without notice in case of emergencies like a bursted pipe in the winter or something (which was common and happened in the unit below me this winter, I made sure to be the top floor unit).

i have indeed,thats why its a bad idea,mainly want to spray when in turn they really seeing if any destruction has been done,how do i know this,i worked for apt complex and thats a safety measure for them,you'd do the same if it was your investment just saying,anyway seen your post and said what,good luck on your journey

 

[vchaz]

Also, some people have posted replies with suggestions on how to stop light from leaking out of my tents. To be clearer, since my post was long winded, the point was that you don’t need to block out the light that leaks out of your tent. A lot of people suggest doing it, but it seems to be overkill unless the tent has a manufactured defect like missing stitching, or a rip in it or something. But unless you have really powerful lights outside of your tent running 18-24hours for veg, patching those light leaks is pointless.

 

[vchaz]

I would be willing to wager you think you cant smell it but others are already aware.

What you descibe would push the smell all around.

We get very used to the smell. To others it can be quite powerful.

That is not correct. People have been in my apartment and cannot smell it at all. The only time I can smell it is when I open the bottom vents, before I have turned on the fans that blow into them. And I actually don’t smoke a lot. I smoke primarily for back pain relief and for help sleeping, so I mostly smoke at night. This means that during the day, there’s no smell from smoking and I’m not just “used to” the smell. I have neighbors that smoke in their units as well, and I work from home fairly often. Every time I leave my apartment and come back I can smell if my neighbors have smoked. The smell from their apartment sweeps into the hallway. But when I go to the store and come back, I can’t smell anything outside or inside of my apartment. I can’t even smell anything inside the tent. I have a second carbon filter/fan combo in the room that I am not even using, but at first thought I might need to use one inside of the tent and outside of the tent because of the positive pressure. Turned out that was not the case. The second one is also sometimes used for a 2x2.5 grow tent that rarely has plants in it because of its size, and mostly is for germinating / veg, etc. anyway, both of my inline fans and both of my carbon filters are rated for 495 cubic feet per minute and only one is inside the 5x5 grow tent, and that’s the one that gets turned on. It is certainly powerful enough to clean the air from the entire room, and it does. Even with the bottom vents open, there is very little air escaping because the air that does escape out of the two small bottom vents just comes right back after being sucked to the fans. Will get some pics tonight hopefully.

 

[jumpincactus]

Hello everyone, I'm a new member here and a newer farmer as well. I have been using grow tents for about a year. I currently run a 5x5 Apollo Horticulture tent as well as a 2.5 x 2 gorilla grow tent lite.

I will post some pictures here as well of my design / setup.

I have carbon filters, inline fans, regular fans, oscillating fans, dehumidifier and humidifier, Cree COB grow lights, some supplemental lights from RapidLED, as well as some flower initiators from GrowMau5.

At night I take in cool air from the outside, and in the day I typically push my warm air out into my apartment and draw in air from the outside if the outside is cool enough. If it's warm outside, I push my warm air outside and draw in cool air from my apartment.

Here is what I've learned about grow tents, which is contrary to a lot of the information you will find online and on youtube:


Light Leaks:
---------------------------
When the lights inside your grow tent are on, and the lights outside your grow tent are off, sometimes we will notice small amounts of light coming through the seams near the zippers and the zippers themselves. A lot of people see this and freak out thinking "LIGHT LEAK! MY PLANTS!!!!!".

While this does indicate that light is able to get out / come in through those seems, we have to evaluate whether or not this is going to be a concern. Let me explain why it might not be for most people: Inside of our grow tents, we have very high light intensity. Outside of our grow tents, we tent to have a lot less light intensity, otherwise we might not need to use a grow tent. While we may see the light peaking out of the tent when our room lights are off but our grow lights are on, try the reverse. Turn your grow lights off and then zip yourself up in your tent, leaving the lights in the room on. You will notice that there doesn't seem to be any light coming into the tent. Does this mean your tent doesnt have any light leaks? Of course not! You've seen them. What it means is that there is more light intensity/light pressure inside of the tent than outside of the tent. If the light intensity/light pressure outside of the tent is enough to penetrate the seams and zipper when the grow lights are off but the room lights are on, you should patch the tent. Otherwise, you really don't need to worry about light that leaks out but doesn't leak in. Most standard 45-60w bulbs that we have in our ceilings are not enough to penetrate the tent. If you have strong lights outside of your tent, perhaps because you don't veg your plants in a tent, then you may also run the risk of light coming into your tent. However, most people don't have that problem.


Air Pressure / Negative Pressue:
---------------------------
Most videos on youtube tell you that you want to have "negative pressure" inside your grow tent. Essentially, you want the walls of your tent to be sucked in when you have your inline fan running and moving air from inside of your tent to somewhere else, perhaps out a window or just into the same room. The fact is, you do not want negative pressure. Negative pressure means that air is leaving your tent faster than it is being replaced. If you have supplemental Co2 in your tent, you are likely wasting it and have very low PPMs. What you actually want, is positive pressure. You want to have so much air coming into your tent, that the sides are not caving in. I have accomplished this by hanging a very large fan, aiming it towards the lights, and turning it on full power when the lights are on. This essentially makes sure that I always have a balanced or slightly positive air pressure. If I were to turn my regular fan off, the air pressure would turn negative again. I will post a video of this as well.

Thats all the thoughts I have for now, I will be back with some pictures of my grow tent design and explanations of everything. Currently I have just a few really smallish plants in my tent, so I would consider changing my design a little bit if I was going for a full canopy. For instance, I have PVC pipe setup so that I can create a SCROG if I need to.

You didn't mention do you have a inline filter so your filtering the incoming air from what your pulling from the outside in? Good way to introduce critters to your grow. If no filter you may want to consider it if you start to have critter issues...….... Peace