How cold is too cold???

[Loc Dog]

I have no income and am in a house with limited amperage and having trouble finding answer to how cold plants can get at night without negative effects and how cold the feed can be with coir using air pots. Basement room I am about to move plants to for flowering was 48F this morning when it was 15F outside. I used to do RDWC and they said below 65F for feed would cause oxygen issues. Hoping to avoid putting heater in tent. I must have fish tank heaters somewhere if feed needs to be warmer. For RDWC they said 68F was ideal. TIA

 

[flylowgethigh]

Mr Flower says if I let mt tent get under 70 then mold will start. I run the dehuey at night for the heat.

 

[Dime]

I have no income and am in a house with limited amperage and having trouble finding answer to how cold plants can get at night without negative effects and how cold the feed can be with coir using air pots. Basement room I am about to move plants to for flowering was 48F this morning when it was 15F outside. I used to do RDWC and they said below 65F for feed would cause oxygen issues. Hoping to avoid putting heater in tent. I must have fish tank heaters somewhere if feed needs to be warmer. For RDWC they said 68F was ideal. TIA

A lot of it depends on the strain,I have had strains die or close to it at 40f outdoors and had some survive snow. Maybe you can cover them at night ? Outdoor I have covered them with plastic and put in old plastic milk jugs and filled them with hot water to survive a frost,perhaps that would work . As mentioned watch for mold or mildew.

 

[RobFromTX]

I find indicas can tolerate temp fluctuations much easier. But ofcourse i only grow indoors

 

[Dime]

I find indicas can tolerate temp fluctuations much easier. But ofcourse i only grow indoors

Yes and they only need a fraction of the light too.

 

[Loc Dog]

Mr Flower says if I let mt tent get under 70 then mold will start. I run the dehuey at night for the heat.

Have you ever been concerned with temperature of feed water? I could use small heater but do not like to where it is damp. Hopefully running 800 watts of LED's will warm it up.

I had been growing GG4 which is very mold resistant but running 8 others to pick the best this run. Always got mold when I tried others.

 

[Loc Dog]

I find indicas can tolerate temp fluctuations much easier. But ofcourse i only grow indoors

I will have to lookup genetics. Just bought 10 different clones, looking for a few keepers. The best are Chimera #3, Fatso, and MAC1. Will check them on seedfinder.

 

[flylowgethigh]

Seeds won’t germinate unless the soil is 70*f, so I keep my reservoir at 73ish

 

[Loc Dog]

Seeds won’t germinate unless the soil is 70*f, so I keep my reservoir at 73ish

Do you use coco or hydro? Might keep all upstairs, and benefit from heating living area instead of heating un used area. Do you know if following VPD chart will prevent mold?

 

[chilliwilli]

Some years ago i saw a growroom in a cellar. They had heating but in winter the ground was still very cold. They used thick foam plates as ground isolation what worked very well. Even with heating the floor was too cold what stunned growth.

Not sure where i picked that up but heating your nutrient solution could help with too cold temps imo. The warmer pots should act as kind of thermal battery for the plants and the room.

With a constant temp u should have fewer mold problems imo. Warm air can hold more moisture. When it cools it gets released as condensation.

 

[Loc Dog]

Found this which I thought was very interesting, regarding VPD. Not just ideal for mold but optimal growth - https://pulsegrow.com/blogs/learn/vpd

 

[herbgreen]

.... cant you use submersible aquarium heater in the tank w/temp control on it ?

Or would that breed some serious algae?

Cold is rhyme with mold and will stunt the crap out of plants

Get yourself an infrared heater....pickup used or reconditioned very efficient secondary heat source

 

[herbgreen]

If your floor is cold

what chiliwilli said Styrofoam bricks or slabs of styrofoam insulation under plants

 

[Loc Dog]

.... cant you use submersible aquarium heater in the tank w/temp control on it ?

Or would that breed some serious algae?

Cold is rhyme with mold and will stunt the crap out of plants

Get yourself an infrared heater....pickup used or reconditioned very efficient secondary heat source

I moved and think I know where some are from RWDC days. For that 68F was optimum for holding oxygen. Above 76 invites bacteria. Not sure if that applies to coco.

 

[audiohi]

With a constant temp u should have fewer mold problems imo. Warm air can hold more moisture. When it cools it gets released as condensation.

This will be a problem.

Large temperature changes from daytime to nighttime will cause the humidity to fall out of the air definitely leading to mold.

 

[Bush Dr]

The coco needs to be above 16*C for growth to continue, heat the feed to 24*C and that’ll keep the roots warm
Wrapping the pots with bubble wrap will insulate the coco during the dark period

The foliage can stand temperatures around freezing as long as the roots are warm

 

[flylowgethigh]

Found this which I thought was very interesting, regarding VPD. Not just ideal for mold but optimal growth - https://pulsegrow.com/blogs/learn/vpd

There are charts with the color bands for the growth phase. Basically the plant starts wet and dries as it dies.

 

[Three Berries]

In the winter with my indoor grows the temps are usually low to mid 70F to ~60F at night. Humidity during the lights on is targeted at the VPD, around 1.10-1.00. But lights off it's limited to 75% RH. I use heaters on my 3 gal buckets to keep the soil at 73F.

Had a mold issue one time on one bud.

Maybe using UV on the intake air?

3 Reasons to Add Ultraviolet Light to Your Mold Remediation Toolbox - Violet Defense

Being based in the Sunshine state, we know firsthand just how many people in the hot and humid south have to deal with the fight against mold. Throw hurricanes into the mix that can accelerate mold growth due to flooding or leaks and you have a large number of homeowners and businesses concerned abo

www.violetdefense.com

 

[Loc Dog]

In the winter with my indoor grows the temps are usually low to mid 70F to ~60F at night. Humidity during the lights on is targeted at the VPD, around 1.10-1.00. But lights off it's limited to 75% RH. I use heaters on my 3 gal buckets to keep the soil at 73F.

Had a mold issue one time on one bud.

Maybe using UV on the intake air?

3 Reasons to Add Ultraviolet Light to Your Mold Remediation Toolbox - Violet Defense

Being based in the Sunshine state, we know firsthand just how many people in the hot and humid south have to deal with the fight against mold. Throw hurricanes into the mix that can accelerate mold growth due to flooding or leaks and you have a large number of homeowners and businesses concerned abo

www.violetdefense.com

I thought about UV on intake. Not sure how to deal with existing mold spores in tent and on plants unless Physan 20 is safe being sprayed on plants. Will have to confirm that. Have a fogger from recent spider mite infestation from buying clones. At last house grew in basement and anything but GG4 would mold over.

 

[goingrey]

The coco needs to be above 16*C for growth to continue, heat the feed to 24*C and that’ll keep the roots warm
Wrapping the pots with bubble wrap will insulate the coco during the dark period

The foliage can stand temperatures around freezing as long as the roots are warm

This does not appear to be true. My tent is at 12C right now and even the plants in coco still seem to be growing reasonably normally. It came as a surprise to me as well.

Obviously this is not recommended. Leaf tips are drooping which I believe is a result of the oxygen issue @Loc Dog mentioned. So they are not happy. But still growing.

I on the other hand am happy. To see warmer temperature forecasts for next week that is. And that I might make it there without having to fire up the heater.

The bubble wrap is a good idea and I might even have some around, thanks!