Ideas for keeping grow tent warm after lights off.

[ManicOrganic]

I am running 10 plants in soil a 4x4x6 grow tent
. Using a 600w hps with cool tube. Charcoal filter and 400 cmf inline fan. In veg my temps were running between 72-75 deg. And 40-50% humidity with the lights and fan on 24 hours a day. I just switched to 12/12 for flowering and the "night time" (which is actually day time becuase i run the lights on at night) is getting down to the low 60's (it was 61 today for the low temp) not only is this not desirable because it is too cold for lights off also but due to the fact that it gets that cold when the lights are off it take 6 or 7 hours for the temps to come back up past 70 after the lights come back on. My question is what do y'all think the best aproch to correcting this issue is. My 2 options i see are to add heat in some way or to regulate my vent fan to bring temps up. More heat seems like a good idea but i would like to avoid using more electricity and i worried about fire hazards from using a heater in the tent. Plus there is really no floor room in the tent to put a heater. Other option would be to some how run heat duct from the furnace to the tent. It is in a small room in the basement that already has heat in it but it still stays in the high 50's low 60s in the room. But i worrie about the smell creeping threw the duct work and into the house also regulating the heat would be an issue since the thermostat for the furnace is upstairs. My last idea would be to put the blower on a timer and have it run on and off cycles to riase the lights on temp to mid 70's and then maybe have the fan turn off for an hour or 2 before the light goes off to get the temps higher so they dont fall as low when the lights are off. And maybe also have the timer set so the fan stays off for the first hour or so after the lights come on to warm it up faster. My concern with that idea is will the up and down fluctuations be more stressful for the plants than the low temps would be? Sorry to be so long winded. I have idea but would like some input from more knowledgeable growers on the best options.

Thanks: mo

 

[troutman]

Electric heater on a thermostat in the same room as the tent set to about 5 to 10 degrees less than daytime.

If won't go on until the light goes off and the temps go down.

 

[Bush Dr]

Raise them off the floor and put 3-4 layers of bubble wrap around each pot

 

[Bobby Boucher]

Probably a moot point, but if you were burning propane for supplemental co2, you could collect and retain most of the heat produced in a tank of water and allow that to slowly disperse in your room during lights off. You could use this method to a lesser effect by simply placing extra buckets of water in your grow to absorb the heat of day. I don't know how effective that would be without using a ton of water, but I do know that this process is what keeps our earth at livable temperatures during the night hours.

Realistically, if you need a quick fix, you are probably looking at an electric space heater. I would make every effort to find a different solution, personally. Insulate the exterior, move your tent off the ground or altogether into a warmer place, run your lights at night, ventilate warm air into the room your tent is in from a warmer part of the house.. turn your central heater up a few degrees and close off some vents where you don't need them, get creative. Maybe even some hot water in an insulated ultra-sonic fogger. A space heater would be my last resort. They start fires and cause electrical problems. Electricity is a dangerous, expensive, and inefficient heat source.

 

[RB56]

I tapped into an HVAC duct in my basement grow room. Only got me 2-3°F. Reduced the load on the space heater I still need to use. I have one of the oil filled jobs, so no exposed heating element. Has a thermostat and does the job on its lowest setting. I was really surprised at how effective the space heater is. It runs in the 6'x10' veg room which vents into the 10'x10 flower room which vents into the basement. I run the exhaust fans as low as I can while still getting odor control and air exchange.

Considered running a ventless propane heater for heat, CO2 and humidity but it didn't survive my risk/benefit analysis.

 

[onavelzy]

Get a piece of 4x8 insulation at a hardware store, cut it in half and put the tent on that to minimize cold floor impact.

if possible, remove the glass from the cool tubes (I've never had one so I have no clue if that can be done).

simple quartz space heater from Walmart, Target, etc. I got this one on close-out from WM. I believe it was $39. it has an internal thermostat that will shut it off once the room reaches the temp you set it at.

thermo regulated vent timer

 

[dansbuds]

I tapped into an HVAC duct in my basement grow room. Only got me 2-3°F. Reduced the load on the space heater I still need to use. I have one of the oil filled jobs, so no exposed heating element. Has a thermostat and does the job on its lowest setting. I was really surprised at how effective the space heater is. It runs in the 6'x10' veg room which vents into the 10'x10 flower room which vents into the basement. I run the exhaust fans as low as I can while still getting odor control and air exchange.

Considered running a ventless propane heater for heat, CO2 and humidity but it didn't survive my risk/benefit analysis.

 

[ManicOrganic]

Thanks y'all. Think my first step im gonna try is to run some flex duct from my central heat to the. Tent its self and see how it goes. Being that im close to the temps i want i think that over the next few weeks the weather is going to get warmer and so will my basement so its just a matter of limping it along tell it will levle off on its own.

 

[SMS65]

I use an oil heater. Depending on how cold the room where the tent is, you could use a ceramic heater. Point a fan at it.

 

[stizzle]

2nd grow tent flip flop pull in warmer air

 

[OldPhart]

2nd grow tent flip flop pull in warmer air

That is what I plan on running next winter, I'm on all electric heat currently, so why waste power just making heat, when I could run the same power through a light bulb. Sounds like a good excuse to run a 4K grow, hehehe. Just tap into the 240V circuits that feed the baseboard heaters, and run a 2K flip/flop with a dehumidifier. I figure it should heat most of the place, it isn't very big.

OP

 

[Chevy cHaze]

I've tried all sorts of heaters, oil filled space heaters included.
In the end I've stuck to plant heating cables form the garden store. 10m cable draws around 100w and you lay it out on the ground below and between the pots.
If the rootzone is kept warm, the plant don't mind low temps during lights off and they heat the whole tent as the heat also goes up and past the plants too.
Works really well for me and in case they get too hot you can always put them on a mech. timer and have them 15min on/ 15min off or 30min on/15 off etc...
less airflow during lights can also be a good idea if there are no humidity problems.

CC

 

[RB56]

I switched from MH to LED last fall and that changed things significantly. The MH lights warmed the entire basement. Made it easier in the winter, but harder during the summer. Tapping into the HVAC and adding the space heater got me from average 63*°F to 70°F. I'd like it warmer, but it's just not practical. I hand water coconut coir, DTW. I used to store my mixed solution containers in the 55°F basement. Made a very big difference when I moved them into the veg room to warm to 70°F before use. We'll see what summer brings.

 

[KONY]

Add another 3x3 or 4x4 tent for veg, then run that tent the opposite time as the other one and duct air over to the tent thats off. Granted you will be paying for more electric, but atleast u will have a seperate veg space. The hard part with this setup is light proofing.

 

[Easy7]

I have an above ground walk out basement. Used to get down to 42f when below zero outside. Built walls with lumber and insulated. Never gets below 60 now. There is also a gas fireplace that can be used when In am awake and at home.

Honestly there are nights outdoors during the season that get below 60. Some varieties hold heat alright.

 

[ManicOrganic]

Like the idea of a 2nd tent and flip flop but thats not in the cards right now. I ran 6" flex duct from one of the bottom vent holes in the tent to the heat duct in the room. So warm air is pulled in at the bottom of the tent and then sucked to the filter at the top then vented back out into the room. Will have to mess around to get it where i want itbut i think its gonna work.. Also plan to get some foam insulation boardand put it under the tent and on the 2 basment walls that the tent is by. And get a pallet or somethig to get the pots off the cold ground and gwt some warm air under them.

 

[RedBeardy5]

Setup another tent and flip flop them. Just saw that was mentioned already..

 

[Speed of green]

i run my dehumidifier all night to keep the ladies warm&dry.

 

[Muleskinner]

Setup another tent and flip flop them. Just saw that was mentioned already..

Same here! Run something at night, like your veg tent. I'm more concerned about cool daytime temps than night-time. The temp needs to get into the mid-70's ASAP after the light comes on or your yield will suffer.

If you don't have another lamp to run I recommend a DeLonghi space heater, or better yet a Cadet 240V baseboard radiator in the area, that is the most efficient electric heat and both are less than $100.

 

[Crippler]

If your going to use electric or any other fuel to create heat why not spend that money on a 2nd tent and get more buds.

Another idea if its your basement you might have access to hot water line? Look up radiant floor heating. You could hook it into your hot water line with a recirculating pump and thermostat. Blow air over it or place inside your tent. Hope that helps.