Battling Low Temps In The Midwest: Basement Growing

tandem

tandem

Well-Known Member
Living in Illinois definitely has it's draw backs when trying to grow indoors, from the high heat and humidity in the summer to battling low low temps and humidity during the winter months.

Right now I'm running a 5 bucket RDWC setup inside a 5x5 AC Infinity tent. 5th bucket is outside the tent and is my actinmg res. I've got 4 ladies growing under a Scorpion Diablo II at around 60%. Lights off from 10am-4pm as it's usually the warmest part of the day in my house. Tent is in the basement, reservoir is on the ground and the buckets in the tent are sitting on blocks to keep them off the ground as well as to maintain re-circulation. My day time temps (lights on) are sitting around 70-74 but my night time lows are still pretty cool, sitting around 60 maybe dipping into the 50's. I REALLY do not want to run a heater, idk why i'm so worrried about it but I am. What do you guys do to battle cold night time temps? The girls seem to be growing a tad slow, I believe they're suffering from the cold nights. I just transplanted them into their homes a few days ago, hoping they perc up soon!
 
tandem

tandem

Well-Known Member
Anyone have any experience running the lights 24hrs for veg? I've read plants need that darkness to basically recharge, use their sugars and what not, but what would produce worse results, real cold night time temps? or cutting them off from a night cycle and just running the lights 24/7?
 
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Delps8

Well-Known Member
tandem said:
Anyone have any experience running the lights 24hrs for veg? I've read plants need that darkness to basically recharge, use their sugars and what not, but what would produce worse results, real cold night time temps? or cutting them off from a night cycle and just running the lights 24/7?
Click to expand...
I grow both autos and photos 24/0 in veg because cannabis does not need darkness to do its Calvin cycle processing. When I grow autos, I'll drop that to 20/4, 21/3, etc. or whatever I need to hit my DLI target.

The temps in your grow room are severely inhibiting growth. The graphic below is from the Chandra paper. The focus of the research was on the impact of varying light levels and temperatures on net photosynthesis in cannabis.

At 20°C (68°F) the net photosynthesis rate is about 7 but when the temp goes to 25°C, that value doubles.

My grows are in an unheated garage in Southern California. Outdoor temps in the winter months drop into the 40's and temps in the garage will get to the low 70's. Seeing that photosynthesis plummets when temperatures drop to the 70° mark, I run an AC Infinity heater during lights out. The heater is $99 and my electricity is…45¢ per KwH so there's a cost involved in running the heater but I believe that the difference in yield makes up for the $20/month cost of running the heater.

1737005409835.png

Leaving the lights on will not only help keep the plants warm but it will dramatically increase yield. Cannabis yield increase in a linear/almost linear manner (depending on whose research you read) as light increases. My impression, having been here in RIU and a few other sites for 4+ years, is that growers provide modest amounts of light to their plants and, no surprise, get modest yields. I get my plants to their light saturation point as soon as possible and routinely run them at > 1kµmol by about week 6.

The combination of high light and hydro is really quite something.

"Aside from CO2, once the inputs to the grow environment have reached the "sufficiency" level, light is the only input you can add that will increase crop yield."
 
tandem

tandem

Well-Known Member
Delps8 said:
I grow both autos and photos 24/0 in veg because cannabis does not need darkness to do its Calvin cycle processing. When I grow autos, I'll drop that to 20/4, 21/3, etc. or whatever I need to hit my DLI target.

The temps in your grow room are severely inhibiting growth. The graphic below is from the Chandra paper. The focus of the research was on the impact of varying light levels and temperatures on net photosynthesis in cannabis.

At 20°C (68°F) the net photosynthesis rate is about 7 but when the temp goes to 25°C, that value doubles.

My grows are in an unheated garage in Southern California. Outdoor temps in the winter months drop into the 40's and temps in the garage will get to the low 70's. Seeing that photosynthesis plummets when temperatures drop to the 70° mark, I run an AC Infinity heater during lights out. The heater is $99 and my electricity is…45¢ per KwH so there's a cost involved in running the heater but I believe that the difference in yield makes up for the $20/month cost of running the heater.

View attachment 5451123

Leaving the lights on will not only help keep the plants warm but it will dramatically increase yield. Cannabis yield increase in a linear/almost linear manner (depending on whose research you read) as light increases. My impression, having been here in RIU and a few other sites for 4+ years, is that growers provide modest amounts of light to their plants and, no surprise, get modest yields. I get my plants to their light saturation point as soon as possible and routinely run them at > 1kµmol by about week 6.

The combination of high light and hydro is really quite something.

"Aside from CO2, once the inputs to the grow environment have reached the "sufficiency" level, light is the only input you can add that will increase crop yield."
Click to expand...

This is exactly what I needed to hear! Thank you brother!
 
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