LOW TEMPERATURES INDOOR GROW

I am having problems with lowish temperatures. 60 night and 68-70 lights on. The plants look healthy 8.5 weeks into flower but look about 6.5 - 7 weeks (50/50 Indica Sativa strain). I have the same strain same age in a smaller room which sit at around 74 day and night and they are far fatter and more dense they look like they will be done in a week or so.

My question is will the colder plants just take longer but end up just as dense as the warmer room plants or have I permanently stunted them.
I need to juggle my electricity bill with the heat I can give them, not particularly for the cost but more to keep my bill looking normal for my electricity supplier as they have already been asking questions regarding high usage, although I suppose an extra 2 weeks lights would probably cost the same as a 2kw heater blasting 24/7.

Back to my question will they just take longer or will I just have to accept a lesser yields as the damage has already been done? I don't want to take them further for nothing.
Flood and drain nutrient temps 62 - 70 - 1.8 ec - 5.6 to 6ph.
Many thanks.

Any pics??

Will try and sort some of both rooms.

The lower temps is pretty srrain dependent, usually just slower growth in veg and purple fan leaves in bloom..

Ive got a flowering room in my basement that is 10-12 degrees cooler than my rooms upstairs. Right now Ive got a RKS that has just been crawling to the finish line down there.. Day 82 after the flip and she needs another 10 days.. Very frosty and dense though.. The highs are 71 lights on..59 lights off.

My experience with autos and cold temps has been additional time until harvest depending on strain. Additional time is split between veg and flower with autos so I get an extra week or two veg time and then flower can take an extra week or two.
Room gets as low as 62F and rarely ever reaches 70F.

Corso312 said:

The lower temps is pretty srrain dependent, usually just slower growth in veg and purple fan leaves in bloom..

Ive got a flowering room in my basement that is 10-12 degrees cooler than my rooms upstairs. Right now Ive got a RKS that has just been crawling to the finish line down there.. Day 82 after the flip and she needs another 10 days.. Very frosty and dense though.. The highs are 71 lights on..59 lights off.

Click to expand...

Very similar temps to mine Corso, it looks like I may have some time to go. Mine are unfortunately a mixed strain, some have grown close to the lights and others not so much.

Cold temperatures reduce transpiration on most strains which will result in slower growth most certainly. So to answer your question yes colder temperatures will produce a slower yet sometimes different quality end product. I've learned keeping your temps low especially keeping your actual bud material cooler than 80 F (75-76 F ambient air temp), easily confirmed with thermal gun, will result in way more flavorful and dense buds.

Constantly "Hot" 70+ temperatures is going to result usually in more fluffy buds that aren't as rich in trichomes and terpenes as lots of it was vaporized off. Most volatile terpines evaporate at around 81 F. So if your buds are getting that hot your quality is going down. Not the end of the world and the smoke is probably going to still be fire but if you can have that extra 10% flavor or whatever then why not? ¯\_(ツ)_/¯

Corso312 said:

The lower temps is pretty srrain dependent, usually just slower growth in veg and purple fan leaves in bloom..

Ive got a flowering room in my basement that is 10-12 degrees cooler than my rooms upstairs. Right now Ive got a RKS that has just been crawling to the finish line down there.. Day 82 after the flip and she needs another 10 days.. Very frosty and dense though.. The highs are 71 lights on..59 lights off.

Click to expand...

Love to hear that they are dense and frosty. Usually you'll get that result with the lower temperatures vs the high temperatures. 59 F lights off though seems sketch but I've been going as low as 64 F this winter... Eeek we'll see how she goes. ¯\_(ツ)_/¯

LED lighting has the immense downside of not producing warmth for the plants.


Under HPS look how the leaves are "praying" or perking up with around a +6 F difference from the LED room.

calvin.m16 said:

Love to hear that they are dense and frosty. Usually you'll get that result with the lower temperatures vs the high temperatures. 59 F lights off though seems sketch but I've been going as low as 64 F this winter... Eeek we'll see how she goes. ¯\_(ツ)_/¯

LED lighting has the immense downside of not producing warmth for the plants.
View attachment 4827700

Under HPS look how the leaves are "praying" or perking up with around a +6 F difference from the LED room.
View attachment 4827701

Click to expand...

I have some vegging under Dual spectrum HPS and the same clones vegging under the new Mars LED (with heater) and to be truthful the ones under the Mars often look tired as the day goes on but the ones under the HPS are always praying and happy. Maybe the Mars are to harsh.

calvin.m16 said:

Love to hear that they are dense and frosty. Usually you'll get that result with the lower temperatures vs the high temperatures. 59 F lights off though seems sketch but I've been going as low as 64 F this winter... Eeek we'll see how she goes. ¯\_(ツ)_/¯

LED lighting has the immense downside of not producing warmth for the plants.
View attachment 4827700

Under HPS look how the leaves are "praying" or perking up with around a +6 F difference from the LED room.
View attachment 4827701

Click to expand...

6*F air temp. Let alone the IR.
I bet the leave temp is more then 10*F difference