Hi all! it has been 27 years since i have grown so i am a little rusty. I have a 55 in x 55 in tent with 4 gorrilla glue plants in it. They are 8 weeks old from seed. i have them in 10 gallon pots under 750 watt hps. the plants are in their second week of flowering. they are about 2 to 2 1/2 feet tall. i topped at the 5th node and trained the branches to spread. a week ago i cut all lower branches out ( about the lower 1/3) a few days later i took many of the fan leaves off. pretty much Schwazzing them. My problem is when the dehumidifier shuts off the rh shoots in the 80s. outside the tent the rh is in the low 40s. i have 3 fans circulating the air above the canopy and and giving the plants 1400 ppm of co2. without the dehumidifier my temps are near perfect without introducing outside air in but with the dehumidifier running the temps rise and the need for the exhaust fan is needed. my dehumidifier is pulling about a gallon of water per day. Is this because of the 10 gallon fabric pots? Any help is appreciated.
A gallon of water per day is fairly normal if you live where ambient humidity is in a moderate range. I have a dehumidifier in a 5x5 with 2 plants in 10-gal bags and I empty about a gallon a day.
The fabric bags do breathe, so I would expect that RH might be a little higher using bags, but not by all that much. Most of the transpiration is given off by the plants’ foliage.
I’d suggest buying an exhaust fan. It’s really important to circulate the air in the tent. Something like this
https://www.amazon.com/AC-Infinity-CLOUDLINE-T6-Temperature/dp/B074XBXFPD
I have a 4 inch for my 4x4 tent. I wish I bought the 6 inch. Keeps track of humidity and temps. It runs only when the rh and temps are above the preset limits.
Let’s see some pictures of the grow!
thanks for the quick response. do you have heat issues or do you just vent it all out?
i do have venting when the temp goes up but since i run co2 i did not want to vent as much as possible. here is your pic from
this morning
The dehumidifier puts out a lot of heat. I vent it from the top with an 8" carbon system.
On your CO2 - unless you have a tremendous amount of light on your girls the supplemental CO2 isn’t effective. You need a lot of light (1000+ PPFD) and higher temps for your plants to use extra CO2. CO2 is useless for the average grower and I wouldn’t worry about venting it out. Ambient CO2 is sufficient.
one of the main ressons for co2 is to be able to withstand more heat as well as bigger production. i will be increasing the lights to 1000 watts next week.
I’ve never researched it, but a fellow local grower claims that co2 is heavier than the air and will sink to the bottom of the tent. I think all you would be pulling out is stale air and a maybe little co2. The exhaust is crucial to get some fresh air in the tent. Also decreases the temps and humidity.
If I may add? CO2 displaces oxygen. Depending on how you are venting and to where, CO2 can be dangerous to your health. My advice would be to drop the CO2 enrichment unless you are doing this commercially, the gains wont offset the potential troubles. I had to respond medically to a couple grow ops where trimmers were feeling sick, nausea and light headed. Their O2 saturation was way below normal. Seems the CO2 was replacing the air in the house as they were using compressed gas with a leaky regulator. Anyhoo thats my thought on the matter. Stay safe and have fun.
that is true. Although I do have a vent setup on a thermostat to keep it about 86 degrees. i have a autopilot co2 meter and a autometer co2 controller. i will go check 3 locations in the tent and see. i will take pics. also cannabian, i am aware of the dangers of co2. i have a co2 detector in my grow room outside my tents.ty
I didn’t take any pics but i found only about 200 ppm difference between the air at the top of the tent and at the bottom. So i have found the answer to my problem is to cool down the outside tent to 70 to 72 and the vent kicks on periodically to cool it down . BTW, the condensation water coming out of the dehumidifier is better than my RO water. only 2 PPM!