hi all..

just wondering what the ideal lights on temp is for a growtent?? with my 400W on, it is currently at 25 C (or 78 F)

is this ok??

for lights out i am using a tubular heater. is this ok?? i cant tell temps as the lights are off;O)

many thanks for any advice. this is my 1st tent grow...

Peace, Wigster

That temp is fine and dandy. Anything between 24-27 is generally good for cannabis, bit lower for seedlings and cuttings.

Night time temps can be 10 degrees lower than day times with no probs.

Or Hir could be right I'm not sure now

But that means as low as 14 which imo is too cold

No lower than 18 if poss as any lower and phosphorus uptake will slow in the plant

Under 15 and it will stop altogether

Owd

Ah cool, cheers Owd. I've been keeping my night temps around 18, may raise it slightly. Sure I read that from somewhere on here.

24-27 is quite a narrow range , I thought about 30 would be fine , am I wrong ?

30c seems ok, my closet is +29c (best I can do) and no signs of heat stress or curly leafs, in fact I've noticed new growth and they are quite healthy looking.

I heard 26c daytime & 16c at night is optimal.

30c is getting over the top and out of their comfort range squaggles.

26c is my chosen sweet spot.

The stomata,pores on the undersides of the leaves open at around 25c.

So at 26c they are just starting to transpire,and obviously as the temp goes up they really start to sweat.

But I've heard Sats like it a bit warmer so maybe their mean temp should be a bit higher.

But I've grown a crop where its been in the high 30's and still got a great result but am sure with lower temps the yield would

have been a bit higher.

But just as important are adequate night time temps as Owd has pointed out as its pointless getting it spot on in the day

if they are gonna be too cold at night,which will impair their metabolic processes.

Can't be sure cos of me being a stoner but I think it was OT1 who said he likes a 10 degree difference between day and night temps? I could easily be wrong though.

e2a: but I have noticed greatly reduced growth at the lower temps.

I might have to pay a bit more attention to temps , I've never worried if it was 29 or 30 . Always kept it above 16 at night though . Very hard to judge the difference in yield with all the other factors involved .

I think what he recommends is a temp range no greater than 10 degrees.

But like owd says if it is 24 at lights on then lights off temps will be too low. The ideal is no change in temp as far as I am aware. My temps have been 26 at lights on, but going too low, at 16 at lights off, so, time for a heater in my room now.

Came across this OT1 Post.....he's talking farenheit - so a 10 degree F differential is about 5.5 degree C.

http://www.uk420.com/boards/index.php?show...ost&p=25878

Also this knowledgebase article again talking farenheit suggests some differential is important for flowering.

http://www.uk420.com/boards/index.php?auto...showarticle=177

That makes a lot of sense right there

HI again everyone..

TOP MARKS to you all.

many many thanks for all your help, links, suggestions, advice on this subject

a never ending source of great information!!

peace
Wigster