high grow tent temperatures

[nastynate420]

I've got a 4x4x6'7" tent that I'm using right now. Temperatures are reaching 81 to 82 degrees when my 600 watt MH light is on. I have an 720 cfm active air 8" fan for exhaust which is connected to my light. I leave the front door to the tent open as passive intake since the biggest passive intake built into the tent is only 4". The temperature reader is set at the canopy level directly under the light. Like the title says temperatures are reaching 81 to 82 degrees. Is there anything I can do to cool it down?

 

[Jnugg]

How many of those 4" passive intake vents does your tent have?

And what kind of tent?

Seems stupid to have a tent that big if it only comes with 4" passive intake socks.

My SJ DR90 (3x3x6) comes with 1' 6" extraction sock,2x 6" light aircooling socks,2x 6" passive/active intake socks,and 2x 6" x 8" passive vents.

 

[Coconutz]

Put the probe in the shade of the cannopy.
Are you running your lights at night?

 

[Jnugg]

Put the probe in the shade of the cannopy.
Are you running your lights at night?

Exactly,you may be reading radiant heat which isn't an exact reading of what the plants are seeing/feeling.

IMO it's best to keep temps between 72°F and 78°F,especially in flower.

 

[nastynate420]

Thanks for the quick responses. I have the temp set at 75 on my thermostat but my fan can't seem to get it down that low. I wasn't going to move the temp/rh reader out of the direct light because I wanted it to be feeling the same as the plants... Is that not how it works? I'm running the lights during the day and night since I'm in veg. Lights off has been from one to seven PM. My humidity is at 40 also, should I get a humidifier?

 

[Coconutz]

Move the probe into the shade.
Run t8 for veg
I wouldnt put a humidifier in the tent. If you can set up the room the tent is in as a lung room that should work. But if youre exhausting the air it wont stay in the room
If youre going to run a higher RH% make sure you have a lot of air movement in the tent.

 

[Jnugg]

Unfortunately a humidifier will add more hear,so no.

If you can get the lights on temp down,humidity should increase a little.

Ideal temperature and RH% would be 72°F to 78°F and 55% to 65% RH.

The bigger your plants get (and the more you have) the more transpiration they will go through,adding humidity to the grow.

Now,you never answered my questions OP...

How many 4" passive intake socks does your tent have and what brand tent is it?

Obviously a 4" passive intake is way too small for an 8" 720cfm exhaust fan.

Rule of thumb is the passive intake should be twice the area of your exhaust.

 

[tokersmoke]

In my experience 81f isnt bad.As long you arent noticing problems then leave it be.The root zone temp is more important.High temps are only a problem when there is low air exchange and movement.Get an intake fan and pull cold air in from under your house.Its not quite like having co2 but fresh air equals c02. my 2c

 

[tokersmoke]

Sorry to jump in asking questions but ive got around 30% humidity in my flowering room.I have searched and see results saying to get humidity to 20%?Then other posts saying what jnuggs is saying.Can you fill me in j nuggs?

 

[Jnugg]

If you do go the route of using an intake fan,the intake fan must be smaller and have less airflow than the exhaust fan in order to keep a negative pressure environment.

If pulling air from under the house or between floorboards you might want to use an intake filter aswell as you could be pulling mold/spores and bugs in with it.

There is about 400ppms of co2 in fresh outside air,which is plenty.

IMO tents aren't air tight enough to warrant real co2 supplementation and co2 supplementation.shouldn't be used unless all other environmental factors are dialed.

 

[Jnugg]

Sorry to jump in asking questions but ive got around 30% humidity in my flowering room.I have searched and see results saying to get humidity to 20%?Then other posts saying what jnuggs is saying.Can you fill me in j nuggs?

Lowering humidity towards the end of flowering (the final few weeks) has been shown or believed to get the plant to increase essential oil/trichome production.

In veg it is recommended to keep RH% between 50% and 65%,as well as the first half of flowering.Once buds begin to fatten up and dense up (around the 4/5 week mark in flowering on 8 to 9 week strains) RH% should be kept around 50% to 60% so as not to run into mold problems.

 

[tokersmoke]

Jnugg thanks for the straight answer.Definately need a filter for the intake.I get really cool air in summer and winter depending on temp i turn the fan speed up or down.Also if you are using a cheapo digital thermostat they will all read different i have two cheapos that read 4 degrees apart. If you can manage it get your home a little cooler keep the thermostat at 70.may be expensive in the summer months.

 

[Jnugg]

No problem tokersmoke,just here to help should some newbies need it.

 

[nastynate420]

The tent is in the basement so unfortunately I can't pull any from under. Smell isn't to much of a worry so I shouldn't have to worry about negative pressure. That being said I don't plan on putting an intake in since I just leave the front door of the tent open anyways which is much more than twice the exhaust area. I can't answer your question quite yet Jnugg since the lights are off until 10, once that time rolls around I'll run downstairs and check. I don't plan on using C02 since I'm not sealed and it would add heat. I may in the future when I build my basement out right and get a dedicated ac down there to control temps better.

 

[Jnugg]

Well what do you plan on doing when you begin to flower them out.

Any light leaks are bad and will delay flowering,cause airy buds (just as too much heat will) and can cause your plants to hermie.

 

[tokersmoke]

If the tent is in the basement id say ditch the tent if at all possible.I wish i had a basement.

 

[tokersmoke]

Love the handle by the way nastynate!!

 

[Jnugg]

Tokersmoke,why ditch the tent?

Without an enclosed structure there will be no light reflectivity to reflect lost light to the plants,cutting down light efficiency and photosynthesis.As well as being one huge light leak in the dark period of flowering should someone go down there and turn on a light.

 

[nastynate420]

I'm not sure I quite follow you? I'm planning on transferring these vegging plants into my basement and upgrading to four lights and ducting the air from the lights outside as opposed to just in my room like I do now. I think I'm probably going to need bigger fans pumping air out though since all I have now is two 8" 720 cfm fans. I may set those up on the lights and get another fan that 12" or 14" fan to dump air out of the room when it gets to hot. I may just nut up though and buy a 3 ton mini-split. The problem with that is I'm renting the home and I don't want to do irreparable damage.

 

[nastynate420]

It seems to me like the mini-split would be the easies then I wouldn't have to worry about all this extra bullshit