Temps Help

[aesthetics1990]

Hi

My tent is sitting at 28C

I've got a 8' RVK fan on (only when the lights on) veg stage so no smell.

Lights on 18/6

Light came on at 5am and when I woke up at 8am it was only 24C ... Now it's 3:30pm and its 28C the highest it's been all day is 28.4C and the coldest it's been is 16.7C (when the light was off last night)

Is my tent taking to long to heat up?

Is my tent to cold at night?

For me temps are the most important in terms of harming the plants so I really need to get this right

Are the temps good or should or change something?

Thank you

 

[rkymtnman]

are you in veg? if so, run your lights 24/0. will be easier to maintain a constant temp. they don't need a rest period.

or are these autoflowers?

during flower, you want about a 10 deg difference between lights on and off.

 

[nomofatum]

16.7C = 62F
28.4C = 83.12F

Those temps seem quite good.

The thing I would want to check is night time humidity. Depending on your setup it may be climbing to dangerous levels at night.

 

[aesthetics1990]

I don't have a humidity checker just a temp one.

I've always been told it's 18/6 during veg and then 12/12 on flowering stage

These are normal cheese plants not autos

Thank you for both of your replies

 

[aesthetics1990]

What's the best temp to try and keep at for best yield results?

Thanks

 

[rkymtnman]

i've done 24/0 for over 6 years. less than 85F is good for veg. about 75F to 80F is perfect. higher humidity in veg, lower humidity in flower.

 

[aesthetics1990]

24/0 for veg 75F - 80F

What's best for flowering mate?

Thanks

 

[rkymtnman]

12/12 for flower. same temps when lights on. lights off you want about 10 to 15 degrees less. and much lower humidity so you don't get mold. a good fan will help keep mold away too.

 

[nomofatum]

There is generally very little or no gain in veg by running more than 18-20 hours of light. You can run 24 if you want, but you effectively are just wasting energy. 18/6 or 20/4 are the two most recommended light cycles for veg or autos.

70-85f is great for both veg and flower.

I would recommend you get a weather station with both humidity and temp.

You don't want your humidity to ever exceed 60% and ideal would be in the 25-40% range. With as much temp drop as you have at night, and no venting, I would expect you likely exceed 60% RH when temps are at their coolest.

 

[rkymtnman]

how is 24/0 a waste of energy? marijuana is one of the classifications of plants that can photosynthesize for 24 hrs a day. any dark time is time the plant is not photosynthesizing (growing). and no, plants don't grow in the dark. they are stretching to their last known light source. it's a defense mechanism. it also keeps internode spacing closer, easier to maintain constant temps and humidity and shortens veg time overall.

guess we have to disagree on that point.

 

[nomofatum]

how is 24/0 a waste of energy? marijuana is one of the classifications of plants that can photosynthesize for 24 hrs a day. any dark time is time the plant is not photosynthesizing (growing). and no, plants don't grow in the dark. they are stretching to their last known light source. it's a defense mechanism. it also keeps internode spacing closer, easier to maintain constant temps and humidity and shortens veg time overall.

guess we have to disagree on that point.

There have been multiple side by side tests on clones to determine ideal light cycles. 24/0 vs 20/4 vs 18/6. And the results always come out the same.

Veg
18/6 vs 20/4 - Almost Identical, tiny advantage to 20/4.
18/6 vs 24/0 - Almost Identical, tiny advantage to 24/0.
20/4 vs 24/0 - Identical no growth increase.

Auto
18/6 vs 20/4 - Almost Identical, tiny advantage to 20/4.
18/6 vs 24/0 - Almost Identical, tiny advantage to 24/0.
20/4 vs 24/0 - Nearly Identical, but 20/4 actually outperforms 24/0 by a slight margin.

Photosynthesis isn't the only process going on in a plant. The use of the sugars created in photosynthesis can't occur with the plant actively in photosynthesis, so effectively the plant will produce as much sugar as it can hold then it has to go into sleep/sugar use mode. If there is a dark phase it will use this phase to use up the sugars. If you run 24/0 it will still stop/slow photosynthesis to use up the sugars. It effectively takes a day nap, then goes back to work collecting more. It seems that the plants need at least 4 hours per day to use up the sugars. If you don't designate when to sleep by turning off the lights they just pick their own timing.