Input needed Re: Light foot print for CO2 SOG tents

jjng5

Well-Known Member
Hello all!

SWIM has two flowering tents that are getting finalized for SOG at 2 plants per square foot. One tent is 4.54 ft x 4.54 ft (= approx. 20.5 sq ft total) and the other is 5 ft x 5 ft (= 25 sq ft total). Also each tent has it's own 20 lb CO2 tank with regulator and Saturn controller. These will be sealed tents. SWIM needs to move the foxy ladies soon as they're between 10-12 inches tall now.

20190406_113445.jpg

To my question... The foot print...

In the smaller flower tent (4.54' x 4.54') there are (2) air-cooled 400W HPS lamps and (2) HLG 324 V2's on a 320watt controller. I tested the LED range with a multimeter and depending upon whether you dim them they range between 150-165 watts each. That totals ~55 watt per sq ft (39 wpsf as HPS and 16 wpsf as LED).

In the larger flower tent (5' x 5') there are (2) air-cooled 600W HPS lamps and (2) HLG 324 V2's on a 320watt controller. That totals ~61 watt per sq ft (48 wpsf as HPS and 13.2 wpsf as LED).

[Measurements taken from a Lux meter with LED's @ 17" height and HPS @ 19" height]
footprint_light.jpg

SWIM goal here is maximum efficiency. Of course both tents could run at 150 watt per sq ft but again, the goal is maximum efficiency not necessarily the biggest harvest. Each tent will run around 1000 ppm of CO2 all throughout flower except for the last 2 weeks will taper it down of course.

The issue at the moment is that I'm not sure that the tents have adequate foot prints for SOG. And I need some outside feedback from experienced advanced growers on the subject. Does SWIM really need two more HLG 324 V2's per tent (basically one hanging above each of the four corners with the (2) HPS hanging more in the centers? Or is four light sources enough here for SOG? SWIM doesn't want to have to spend more money on lights and electricity if the gains will be minimal but if it's going to make a huge difference towards significantly improved efficiencies... then I guess SWIM has to break down and do it.

SWIM took some Lux measurements of the smaller 4.54' x 4.54' tent with the (2) HLG 324's and the (2) HPS lamps running. Before I get yelled out, I recognize that Lux does not accurately measure LED lamps I know. But SWIM doesn't want to spend hundreds of dollars on a PAR meter when he knows he has efficient lamps -- SWIM just wants to try and gauge the foot print and even out their spread.

Take a look...

20190406_113500.jpg
The young ladies getting ready to move to their new home:
20190406_113751.jpg
The larger flower tent (5x5):
20190406_113931.jpg
5 foot mother bushes with their bush out! (Yes taller than the water heater!)
20190406_114002.jpg


I appreciate anyones input on this, especially from any SOG or SCROG growers. I know that most people automatically push for more light. But I'm really trying to consider if this setup is going to provide near peak efficiency (esp. with CO2 injection) or if (2) more HLG LED's per flower tent (4 more total) would make a huge difference or just minimal gains?

Thanks everyone!
 
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Renfro

Well-Known Member
You could always dangle an auto cob in each corner where it's not getting as much light.
 

jjng5

Well-Known Member
You could always dangle an auto cob in each corner where it's not getting as much light.
The ones I found are around $120 / ea -- HLG QB's are about that much. So you agree, the corners of the tents need more lux for flower? I am hoping with CO2 that the light would be used efficiently. What do you think?
 

jjng5

Well-Known Member
At the same light heights SWIM repositioned lights side by side in the pattern they would need to be positioned for one LED HLG per tent corner. On the LUX meter the corners were ~40k Lux, directly under the LED ~65k, and at the center point between the LED lamps and HPS lamps maxed out at ~80k LUX. Do you think this is more suited for maximum efficiency for a SOG CO2 grow? SWIM has never done SOG or CO2 or LED so this is definitely a bump up. Thanks!
 

jjng5

Well-Known Member
Please STOP saying SWIM!!!

Co2 in a tent is a waste of gas. It will seap and leak out hugely.
Even if you duct tape all the air exchanges down? I was going to use a fan to blow air in and see where it tries to escape to tape down any pin holes, etc. ?

What do you think about the light / lux foot print?
 

DemonTrich

Well-Known Member
If your tent during lights on, is in a dark room, and you see dots of light poking thru, that will be your co2 also escaping the room. The seams of the tent shell are not air tight, and will also leak out co2.

Its not too costly to build a room from 2x3 (2x4 preferred), and a few layers of panda film, screws, stapler, and a few rolls of quality hvac tape, and your much better off.

HD sell a product called reflectix. I use this on the inside when building grow rooms for clients. And 6ml black contractors film on the outside.
 

jjng5

Well-Known Member
If your tent during lights on, is in a dark room, and you see dots of light poking thru, that will be your co2 also escaping the room. The seams of the tent shell are not air tight, and will also leak out co2.

Its not too costly to build a room from 2x3 (2x4 preferred), and a few layers of panda film, screws, stapler, and a few rolls of quality hvac tape, and your much better off.

HD sell a product called reflectix. I use this on the inside when building grow rooms for clients. And 6ml black contractors film on the outside.
I asked the guy at the local Hydro shop yesterday and he said that he recommends trying to leak proof a tent with HVAC tape and around unused zipper area's but he said that a 20 lb CO2 tank should last a month with a tent, which isn't terrible. He recommended not opening the tent needlessly and only opening it towards the end of flower period when CO2 is vented out anyways. 1 tank per month isn't terrible when they cost $20 to refill.

What do you think? Might eventually look to go towards the Panda film or building foam or whatever in the future, esp. if CO2 waste becomes a big issue. The tents are just so convenient to work around between lights and ventilation, etc.
 

DemonTrich

Well-Known Member
Good luck using 1 tank a month. I'm at 1 tank per 1.5 weeks.

Plant using co2 will also determine usage, as well as leaking.

And a grow store employee is just a salesman, nothing more.

I also never vent my sealed room. A sealed room means just that, sealed.
 
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jjng5

Well-Known Member
How are you controlling temp and humidity?
@TintEastwood is this question to me or @DemonTrich ?

For myself I have two new 30 pint units of these small skinny mini units with external water hose drainage:
dehumid_040919.jpg

I also have Titan Saturn 6 Controllers in case heat goes above the dead band. Humidity should be okay since there's a dehumidifier connected to an environmental controller inside the tents and temperature shouldn't be an issue really since I'm using LED's with external controllers placed outside the tents and air-cooled HPS lamps on separate ventilation. BUT just in case it does creep above the temp range on a hot day (even though CO2 wants a higher temp range anyways)... the environmental controller will dump the tents atmosphere on those rare occasions to keep temp's in line.

As for @DemonTrich I'm not really sure. He said he doesn't use tents, I'm not 100% sure there. Sort of curious what he's doing for everything myself.
 

TintEastwood

Well-Known Member
@TintEastwood is this question to me or @DemonTrich ?

For myself I have two new 30 pint units of these small skinny mini units with external water hose drainage:
View attachment 4314799

I also have Titan Saturn 6 Controllers in case heat goes above the dead band. Humidity should be okay since there's a dehumidifier connected to an environmental controller inside the tents and temperature shouldn't be an issue really since I'm using LED's with external controllers placed outside the tents and air-cooled HPS lamps on separate ventilation. BUT just in case it does creep above the temp range on a hot day (even though CO2 wants a higher temp range anyways)... the environmental controller will dump the tents atmosphere on those rare occasions to keep temp's in line.

As for @DemonTrich I'm not really sure. He said he doesn't use tents, I'm not 100% sure there. Sort of curious what he's doing for everything myself.
Directed to you. Some keep the environment surrounding the tent at proper temp/humidity. Then use that air for circulation thru the tent intake/exhaust.

For my situation, an unsealed room or tent with no dedicated AC was a complete fail.

@DemonTrich has a killa setup from what I've seen in other threads.
 
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jjng5

Well-Known Member
Directed to you. Some keep the environment surrounding the tent at proper temp/humidity. Then use that air for circulation thru the tent intake/exhaust.

For my situation, an unsealed room or tent with no dedicated AC was a complete fail.

@DemonTrich has a killa setup from what I've seen in other threads.
How high did your temps get? What type of lights were you using? I believe with CO2 at the right humidity you can go upwards of 95 degrees F.
 

TintEastwood

Well-Known Member
As an example from last year....102 would have been my intake air temp. Humidity 25%. Winter....the opposite. (50degrees/80%)

I run low 80s, under a pair of 315 cmh, and 240w cobette.

20190407_111359_HDR.jpg
 

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jjng5

Well-Known Member
As an example from last year....102 would have been my intake air temp. Humidity 25%. Winter....the opposite. (50degrees/80%)

I run low 80s, under a pair of 315 cmh, and 240w cobette.

View attachment 4314837
So you're suggesting keeping the external climate outside the tent comfortable? I have additional dehumidifiers and will have to use the room's air conditioning to provide external environmental atmosphere if that's what you mean?

How did your temps get so high? Did you have a climate controller in use? Just curious for my own sake.
 

DemonTrich

Well-Known Member
How high did your temps get? What type of lights were you using? I believe with CO2 at the right humidity you can go upwards of 95 degrees F.

Please do not go above 85* (legit 85*f tested on numerous gauges in the same spot), unless you like fluffy BS buds. T happened to me. This is only until the last 3 weeks of your flower cycle. Then you need to lower a bit, weekly depending on how you finish your run. Dialing in a grow is KEY before adding co2. Co2 can and will bring out all your growing weaknesses 1000%. It's not a bandaid, it boosts weight, but only if your on point.
 

TintEastwood

Well-Known Member
I have....
100 degree air outside.
100 degree air surrounding my tent.
20% Humidity.
.....
No fan and/or controller is going to lower the air temperature.
I can create a high flow vortex of 100 degree air.
......
Thats with no lights on.
Turn on 800+ watts of lighting.
Forget about it.
......
In my sealed room.
My AC has a thermostat.
My dehuey has a humidistat.
All good.
 

DemonTrich

Well-Known Member
20180528_191116.jpg I also use a master green house controller with fuzzy logic. Set what ever day and night temp and rh with deadbands, then set co2 my constant level all the time, also with a deadband.

BUT there is trick to not using your controller max amp input and tripping it's own breaker.

4x 315 Cmh
Co2
 
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jjng5

Well-Known Member
I just picked up 4 more QB's -- this time QB96's to try and run as much as possible on QB's to try and keep temps down. I'd still like to find a place to plug in some air-cooled HPS use either during the middle weeks of flower to bulk up the buds ... hmm.

I was between these two options:
board_options.jpg
I went with the option on the left for slightly improved intensity and quality of red light spectrum -- very usable light even compared to 3000k QB boards. Pretty impressive blend of chips. LED's alone take me around 38 watt per sq foot with ( 8 QB's per tent. Now need to figure out where to fit the air-cooled HPS lamps for some added benefit... hmm...
 
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