Optimum temp/humidity throughout a plants life?

WhAcKeD · 10-09-2007, 11:34 AM

Quote:

It's OT for this thread, but 60% RH is good for veg/stretch. By peak bloom it's better to have it down in the upper 40's to avoid mold. Very low RH inhibits growth, and increases susceptibility to pests, diseases, and nutrient burn. It does however stimulate THC production; if you're going to try it, the best time is during the ripening phase (last couple of weeks before harvest) when THC production is peaking and there's little growth. For followup discussion of this subject, a new thread in the growth forum would be best.

Penguin posted this great piece of info and it got me thinking, what is the optimum humidity level throughout the plants life?

For instance: Preveg - Veg - Early Bloom - Mid Bloom - Late Bloom:
60 - 60 - 50 - 40 - 20*

What is optimum temperature?
75 - 80 - 80 - 80 - 80*

*Under a 1000w HPS, sealed cabinet, w/ co2, sativa.

*outdoors* · 10-09-2007, 12:13 PM

Farmer Brown · 10-09-2007, 01:52 PM

I've read that plants like the temps to be higher, 85-90, when adding CO2. I think it was in one of Cervante's books.

GreenDragon2k · 10-09-2007, 01:55 PM

Quote:

Originally Posted by Farmer Brown

I've read that plants like the temps to be higher, 85-90, when adding CO2. I think it was in one of Cervante's books.

they might "like it" as in grow faster, but the bud structure and density will diminish rapidly above 86 degrees F and arguably -- have less potency as well.

even using co2 i prefer to keep my temperature approx 76 - 82f to keep the buds nice and tight

without it, I'd say 75 f is perrrrfect

dont forget -- a nighttime temp of 70f

DLA · 10-09-2007, 02:00 PM

I thought you asked about humidity...anyway...it' also depends on other items as in Co2 and your filters too much and your carbon filters stop working.

I keep my humidity at 40 to 60% through the whole grow...makes it easier for me not adjusting in the middle..

ChiaScrOG · 10-09-2007, 04:28 PM

Quote:

Originally Posted by GreenDragon2k

without it, I'd say 75 f is perrrrfect

dont forget -- a nighttime temp of 70f

I would like to add that in the first part of 12/12 if you keep the temp closer to the daytime temp, you get less stretch. The more gap in temp the more stretch.

So its important to keep that in mind when you are looking at your plants and the amount of space they will take up in your grow. Its a great way to fine tune size without getting mid-evil on your plants .

«..»º©º«ChiaScrOG»º©º«..»

WhAcKeD · 10-09-2007, 10:38 PM

Hey Chia, does that mean that ideally the temp will be consistant day to night until the stretch is finished? I thought I read that ideally they should have a 10 degree F diffrence in temp throughout 12/12. And how do you then "fine tune" your plants?

WhAcKeD · 10-13-2007, 05:32 PM

Well I don't know where I read that, I can't find it. Any help here?

alteredego · 10-13-2007, 11:10 PM

Quote:

Temperature control

The easiest and most under-used way to control internodal stretch is temperature control. Plant internodal length is directly related to the difference between day and night temperatures – the warmer your day cycle is as compared to your night cycle, the greater your internode length will be. The opposite also holds true; the closer your day and night temperatures, the shorter your internodes will be. Ever notice how as the warmer summer months approach, your plants begin to stretch? Part of this problem may lie in an overall hotter grow-room, but a larger factor is the increased difference between day and night temperatures.

Lets look at putting this to play in your grow room. Maximum temperatures should ideally never rise above 26°C, so you must do everything you can to prevent your room getting too hot (run lights at night, use exhaust fans, air conditioners, etc). An ideal temperature range is 24-25°C when the lights are on, and 22°C when the lights are off.

The temperature technique is most effective under a 12/12 light regime, which is ideal as this is when cannabis stretches the most. When the light cycle is brought to 12/12 we will raise the night temperature to the daytime level of 24-25°C. Space heaters on timers work well for this, and max/min type thermometers are ideal for
tracking temperatures.

It is during the first 2-3 weeks of the flower cycle that most strains begin to lengthen internodes, making it a very important time to control temperature, as this is when the framework for future colas is built. After this 2-3 week window we need to drop the night temperature back down to 22°C, as this is where the plant is happiest.

As floral development begins we need to keep in mind that the total size of your buds is determined largely by average daily temperature, provided it does not exceed optimal. So if you are letting your day temperatures drop below 24°C or your night drop below 22°C, you are costing yourself in overall weight and harvest.

Once your buds have reached optimal size and and you have begun the flushing period, you may consider dropping temperature down to 17-19°C for the final week or two. This drop in temperature triggers anthocyanin production, which intensifies the colour of the floral clusters and makes for a showier bud, especially with "purple" varieties. This final temperature change is not always feasible and can be omitted.

For extreme height control you may even use warmer night temperature than day, but be very careful when running settings like this, as even a zero difference between night and day temperatures will lead to leaf chlorosis (yellowing) after 2-3 weeks.

Some things you will notice while using this technique are a change in the leaf angle, upwards during warm days and downwards during warm nights. There is also the chlorosis if this is done for too long. Neither of these symptoms is nutrient related and will fix themselves when the temperature is changed back.

Found at CC.

*outdoors* · 10-14-2007, 12:52 AM

This is interesting to me.... My plants inside the GH had way more stretch than the girls in pots outside and the girls in the ground outside.

The temps in the GH are higher in the day time and about the same at night as the outdoor temps. So the swing is greater in there and the stretch is greater in there.

Peace- OD

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