L
lilvexed
- 2
- 3
Hello thc farmers!
So a quick wrap up before we get into the subject; Having 3 autoflowers in 3x3x5 tent. Plants are grown in 5L perlite Hempys and one in small 2L coco hempy.
Ventilation: "passive" intake. Fresh air comes from the outside (it's ducted with 125mm tube from the room ventilation to come inside the tent)
Exhaust: 4" Carbon filter and 6" Vents VKO125 inline fan drawing.
So everything was fine until the plants stretch phase slowed down. RH used to be stable 40-50%. Now plants just entered into 7th week and the RH has started to creep up sometimes up to 70%.
Temps are in control between 21-24C when lights on and 19-21C lights off.
I guess the relatively high humidity has messed up VPD and plants do "sweat" aka respirating a lot during lights ON. I've understood when the air being too moist the stomata does not function properly and it causes this kind of tip and serrates being burnt and pointing upwards:
During the stretch phase they were doing fine with 2.1-2.3 EC. Now I've lowered EC down to 1.6-1.8 but the new feed didn't have an effect.
I'm having this kind of cheapo extraction fan on the filter drawing.
And this is what gets me confused. The product description says "max draft 185m3/h" So does this fan actually draw 185m3/h(?) and minus ~15% in airflow due the filter?
So that draft should be enough to create almost a little negative pressure inside the tent (0.9m x 0.9m x 1.4m = 1.1m3 tent volume)
And the weirdest thing is if I plug off the fan the temps will raise up to ~26-27C - So the filter is definitely sucking something, but apparently the moisture wont get ventilated enough. Don't really get this… Even at the duct end I can feel by the hand that some warm and prob moist air comes out, but tent RH wont get stable in between the scale of 40-50% in tent.
Do I need a better extraction fan? Carb filter being used only for about 4 weeks so basicly brand new and the pre-filter looks clear.
Also I've tried to play with the nutes in range of 1.6-1.9 EC and tried Potassium from 290ppm down to 210ppm, no effect. Calcium goes about 120ppm and Magnesium 45-55ppm.
Well I prob forgot to mention something, but hit me with the more spesific questions if needed!
Thanks for the help :)
PS. Plants now on day 44. Looking OK, but every time I open up the tent moist warm, almost moldy smell comes out. Worried about the mold and or pests.
So a quick wrap up before we get into the subject; Having 3 autoflowers in 3x3x5 tent. Plants are grown in 5L perlite Hempys and one in small 2L coco hempy.
Ventilation: "passive" intake. Fresh air comes from the outside (it's ducted with 125mm tube from the room ventilation to come inside the tent)
Exhaust: 4" Carbon filter and 6" Vents VKO125 inline fan drawing.
So everything was fine until the plants stretch phase slowed down. RH used to be stable 40-50%. Now plants just entered into 7th week and the RH has started to creep up sometimes up to 70%.
Temps are in control between 21-24C when lights on and 19-21C lights off.
I guess the relatively high humidity has messed up VPD and plants do "sweat" aka respirating a lot during lights ON. I've understood when the air being too moist the stomata does not function properly and it causes this kind of tip and serrates being burnt and pointing upwards:
During the stretch phase they were doing fine with 2.1-2.3 EC. Now I've lowered EC down to 1.6-1.8 but the new feed didn't have an effect.
I'm having this kind of cheapo extraction fan on the filter drawing.
And this is what gets me confused. The product description says "max draft 185m3/h" So does this fan actually draw 185m3/h(?) and minus ~15% in airflow due the filter?
So that draft should be enough to create almost a little negative pressure inside the tent (0.9m x 0.9m x 1.4m = 1.1m3 tent volume)
And the weirdest thing is if I plug off the fan the temps will raise up to ~26-27C - So the filter is definitely sucking something, but apparently the moisture wont get ventilated enough. Don't really get this… Even at the duct end I can feel by the hand that some warm and prob moist air comes out, but tent RH wont get stable in between the scale of 40-50% in tent.
Do I need a better extraction fan? Carb filter being used only for about 4 weeks so basicly brand new and the pre-filter looks clear.
Also I've tried to play with the nutes in range of 1.6-1.9 EC and tried Potassium from 290ppm down to 210ppm, no effect. Calcium goes about 120ppm and Magnesium 45-55ppm.
Well I prob forgot to mention something, but hit me with the more spesific questions if needed!
Thanks for the help :)
PS. Plants now on day 44. Looking OK, but every time I open up the tent moist warm, almost moldy smell comes out. Worried about the mold and or pests.
