Battling Low Temps In The Midwest: Basement Growing

[tandem]

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!

 

[Absorber]

Without adding a heater the only thing that comes to mind is to lift light a little bit and run it at 100% to add more heat to the tent

 

[tandem]

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?

 

[Delps8]

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?

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.



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]

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."

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

 

[Woedae]

I've always been under the impression that plants should have a respiration phase.

 

[coreywebster]

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?

Presumably you're going to flip them to 12/12 at sonepoint so I'd be more focused on getting the temps right , they're already low


Have you seen the ac infinity terraformer?
I think that's what it's called.
It can duct the heat in so you aren't heating the entire basement, just warming the Incoming air to a better starting point

 

[coreywebster]

I've always been under the impression that plants should have a respiration phase.

They can perform all the functions needed in lights on , whether they can perform them at the same efficiency is another question

 

[Absorber]

Presumably you're going to flip them to 12/12 at sonepoint so I'd be more focused on getting the temps right , they're already low


Have you seen the ac infinity terraformer?
I think that's what it's called.
It can duct the heat in so you aren't heating the entire basement, just warming the Incoming air to a better starting point

Spiderfarmer have a ductable heater aswell that looks the goods

 

[thumper60]

You dont mention RH an that spikes with light out, seems you will need a dehumidifier at some point they toss a bunch of heat as they lower RH.

 

[Triplefastaction]

Upper-upper Midwest basement here …

I pissed away lots of $ trying budget ways of keeping my temp up And my humidity down. It just wasn’t happening.

In-tent heater or the new ACI one. Exhaust into lung room. Big ass expensive dehumidifier in lung room.
Unfortunately, both of them run pretty much 365/24/7 and it ain’t cheap. But no different than excessive heat I suppose.

You can have successful grows at 70f/58f. They just aren’t as fun or as fast. Good luck.

 

[Billy the Mountain]

Every environment is different but I live in the upper-Midwest as well and ONLY grow in the winter due to the temps. I grow in a small bedroom located in a large basement. If anything, this environment has been a blessing. I generally exhaust back into the "lung room" to conserve heat and CO2 but can exhaust into the basement if required. Night temps can get a little low but that's never been a problem for me. Occasionally, I'll add a little 200w space heater if it's bitter cold but 99% of the time a cool basement is ideal for growing.