Experiment: 36"x20" (3x1.6) sealed tent - 300w GH LED

porrista

Well-Known Member
So, I was fooling around in youtube 2 weeks ago and saw a video of a guy explaining how he would circulate air in a tent in a slower basis if CO2 was provided and if temps were increased and a lot of info about airflow and carbon filters when it occurred to me that I could use CO2 to take advantage of the high temp and humidity I usually get in my tent. I saw a bottle hanging from the top of the tent and the guy claimed that bottle produced enough CO2 for a month in a 4x4 tent.

I live in a hot and humid region and my tent is located inside a closet, water evaporation was exhausted into the same closet by a regular 6" hanger fan coupled to the upper vent, but this posed a problem: the light would scape from the vent into the closet, reducing stealthiness; I solved it by keeping the closet door always closed but a couple of times I woke up in the middle of the night to find out I forgot to close it before going to bed. Also, water evaporation would go entirely into your closet and room, so the entire airflow gets more humid. I had to get a dehumidifier for the room and it was taking it around a week to get my room from 90% to 60% but the tent continued to be the source of vapor and its inside was always 70%-90% it was getting out of control and I was already thinking on what to do.

I also remembered a friend told me the heat from HPS would make the plant sweat more and thus take more water, and thus more nutes, and this produce more yield than LED just because of that factor.

Initial setup and background:
I've been running this tent for almost 2 years with a P150 LED, a couple of 12v 6" hanging fans, one for exhaust as described and the other for airflow inside of the tent. Temperatures inside of the tent of around 27C (80.5F) and topping 30C in the most hot days. I have always grown within a Humidity range of 65%-90% (really) and I never had mold problems in the past during bloom, lucky me.

Only once I used CO2, in my very first tent grow, I never used it again cause I thought it wasn't necessary for my poor lightning. Back then I sued a gallon with sugar+yiest and a bubble counter so I knew how to produce CO2 cheap and fast.

Strain is Great White Shark from Greenhouse. I had 3 of them in the tent, 2 were clones from a couple of seeds I had to chop before bloom cause I moved to a new place, and 1 was the last seed out of 3 I had. The clones were performing really poorly compared to the seed and the seed was planted in a mix of canna coco + perlite of around 85-15 respectively. ( I recently changed that mix to 60-40 ). The clones were overwatered, not consuming enough water so I was watering the seed once at week and the clones never.. never since I initially watered the pot, and they were of course stunt.

Current Experimental Setup: I took the 2 clones out to a separate tent, in a different room just to see if they would recover, drilled a bunch of holes on the pots and they have been indeed recovering pretty well. They will serve as basis for another 2 new experiments I have in mind. Left only the seed plant in the experiment tent, put on a net and got her flat, covering maybe 50% of the area on her own, then I put the dehumidifier below it, and sealed the upper vent, put the fan that was exhausting air on that vent hanging down and throwing hot air to the right bottom of the tent, to the 2nd fan that moves the same air to the pot and below the canopy, making sure I had an even leaf movement, not to strong btw, just a slight movement. Sealed the bottom vent that was supplying fresh air and now the tent was completely sealed and recirculating hot air from the top to the bottom ( sounds crazy I know ). Then I replaced the P150 (3 fans) by a GH300 (2 fans).

Turned the thing on except for the dehumidifier and went for a couple of races (NFS Shift), came back I couldn't see a thing on the hatch, it was completely fogged and full of water drops, everything was wet inside and humidity was 99%, temp was 31C (87.8F). Turned the dehumidifier on and went to build the CO2 bottle. Humidity has been constant at 60%-80% since then.

The CO2 falls down from a hose hanging right on top of the canopy and it gets raised by the bottom fan throwing hot air into the canopy and going. 1/2 cup of raw sugar + 1 tbs of yiest have been producing 10-20 bubbles per minute for a week. Not sure of how many PPM. I was hoping to see how growth was affected and trusting 1 bottle was enough for 4x4 so it should be enough for 3x1.6 and one single plant.

It has been 1.5 weeks since then and the plant has now covered around 80% of the net, it is also about to end week 2 of transition after 4 weeks of vegging.

So now my room stays steady at ~75% of humidity and the tent between 60% and 80% since then, perhaps a little more humid when I water but it gets regulated fast in around 2hrs.

I've been logging how much water it takes and it now and she has been busy since the new setup was implemented.
 

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porrista

Well-Known Member
1- I was looking for a way to edit the title cause I ended up moving the plant to the bigger tent the day after I posted the thread so now it is a 4x4 tent with 2x300w LEDs.
2- I know no one cares, so what the hell. I always wonder why I almost get no replies to my threads, perhaps it is because I ask for no help and it is a bit of showing off. In reality I post cause am exited with the plants and have no one to talk to about it ( or I don't want to talk about it to anyone I know ). But anyway, I keep posting cause years later, regardless of what happened to my computer, I can always comeback and look at the pics of my girls and stuff.
3- Since the last post:
-- Transplanted to a bigger pot cause it was taking 2L daily and was not yet full in flower stage.
-- Moved to a bigger tent, cut the net and left it there hanging from the plant.
-- Added 1 gallon of CO2 mix.
-- Decided to use the smaller clon for seeds (I really liked this strain) + around 7-10 grams, the second stronger clone to yield around 1oz and take advantage of that extra space.
-- Been spraying Canna Boost daily on the leafs and bud spots. Today I added 4cc to 2L of water for the root zone.
-- Been spraying coloidal silver on 1 branch of the lowest clone.
-- Bit more LST as branches come up.
-- Bit LST on the clones.
-- Left the bigger plant dry for 3 days without watering, there were no signs of dehydration at all. Leafs are dark green with evident new leaf grow in a daily basis. in the mornings you can see light green on tops and at the end of the day you will see those light green leafs are now teenager leafs in dark green.
-- Stem is really thick, probably product of the LST + pinchin (Supercropping) I have the feeling that I saw it more thick before, right after the dry period and before I watered it last night.
-- Last week, before the dry period, I watered with 1/2 AB + PK + zhym for 3 days. Last night I used A+B + Calmag + zhym. This morning I used 1/2 AB + PK + Boost again for the last time + Boost on the leafs.

Humidity: 75%-90% depending on the time of the day.
Temp: 28-30 (this tent keeps a loot cooler than the other tent)
CO2: NA, I don't have a meter.
Air: Still a sealed with no air exchange other than when I open it every day or every other day to water the plants. I try to open a window not a floor level to avoid letting the CO2 escape if there is any down there.
 

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porrista

Well-Known Member
I had a small MG deficiency due to the PH being too high. Applied calMag foliar, did a flush, I wasn't able to get the runnoff below 6.5. I read somewhere that I should focus on what goes in, not what goes off, so I just let it dry for a couple of days and applied 5.8 in full dose of everything. It seems to be recovering.

This happened after I applied a couple of full dosis of PK.. :-(
 

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