Acceptable humidity percentage??
- Thread starter arkandsaw
- Start date
Closetgardner
Well-Known Member
75% max 50%min.imo
chipmunkproof
Active Member
over 60% and you run risk of Powdery mildew and mold
x420xColtonx420x
New Member
Other than gaining mold, if grown at a humidity of 85%, would it grow crazily or would it have it's growth stunted?
Closetgardner
Well-Known Member
Yh in flower. He's talking about veg
Straightjacket
Well-Known Member
My veg room is a partition in the flower room. So the plants in veg are the same as flower. In the summer I use a dehumidifier keep it 45 to 55 %. The plants in veg dont seem to mind. right now sucks, its been between 32 and 44%. usually under 40. the plants in veg are doin ok but I'd like to raise the humidity.
chipmunkproof
Active Member
Sorry i assumed he was talking bout the whole grow
chipmunkproof
Active Member
I would assume it would stunt but truthfully my humidity never gets that high over 70% where I live so I have no experience with it.
doobieboy420
Member
right now mine is between 35% and 40%
LUDA
New Member
TEMPS AND HUMIDITY.
A humidity and temperature gauge are essential in any growroom. Daytime conditions should be 70-80 degrees without co2, 80-90 degrees with co2 until the last two weeks when daytime temps should be kept between 70-80 and co2 can be reduced to adjust for the lower metabolism. Night temperatures should be kept above 60 degrees to prevent stress. It is preferrable during flowering to have a night temperature drop of 10-20 degrees to stimulate flowering hormones and reduce stem elongation.
I find that low humidity causes stress on plants. I recommend 50-60% humidity until the final 2 weeks of flowering. At this point, the humidity should be lowered as much as possible to encourage the plant to seal and protect itself with additional resin. (I am able to get the humidity to go as low as 31%) I have been able to frost things up considerably this way. The higher humidity levels prior to final ripening reduce salt levels within the plant tissue and encourage healthy, more lush growth.
MORE ON TEMPS AND HUMIDITY.
TEMPRATURE AND HUMIDITY GUIDE.
The Environment.
Air, temperature and humidity are closely linked and all are important factors in providing a good environment for your plants. Outdoor growers are at the mercy of the elements so control of the environment is limited for them, for indoor growers however things are different. Luckily the environment in your average heated house is close to the ideal conditions for cannabis growth. This makes indoor growing the best option in cooler climates like the UK.
Air.
Unlike us plants can`t move to get fresh air. When kept inside or in a greenhouse they can suffocate if the air around their leaves is not changed. During the night when plants are working on their roots and not producing any of their own oxygen the need for fresh air is even more important. To get the best from your plants therefore use circulating fans and ventilate or use extraction fans day and night.
CO 2.
Cannabis plants need to be able to extract Carbon dioxide (CO 2) from the air to use as a building material. The amount of CO 2 a plant can use depends directly on the amount of light it receives. Low light gardens (around 1000 lumens per sq. ft) will not be able to use any more CO 2 than is available naturally in the air. Higher light gardens can use more CO 2 but only if it is delivered in the right place, at the right time, at the right temperature and in the right amounts. Unless you have no fresh air ventilation at all or are a commercial grower CO 2 injection can be a lot of hassle and expense. It`s easier just to constantly pump in fresh CO 2 laden air.
Oxygen For Roots.
For healthy growth you need to make sure a plants roots have direct access to oxygen on a regular basis. In pots this means allowing the medium to dry out a bit between waterings. In hydroponics it means making sure you don`t saturate your medium too much. Flood and drain only once or twice a day or use NFT systems where most of the roots are out of the medium anyway. Healthy roots are bright white while roots starved of oxygen will start to go brown.
Temperature.
Cannabis can survive in temperatures ranging from freezing to 100 degrees but such extremes will slow growth and lower potency. For the best results during a plants day time keep temperatures between 70 and 85 degrees. At night aim for between 50 and 70 degrees. If heat becomes a problem try timing the light cycle to come on at cooler times like during the night. Using a thermometer with a min max setting will also make sure you are aware of temperature fluctuations that take place when you are not around.
Extra Heating Indoors.
Adding more HID lights is a good way to increase the temperature in a grow room. They kick out nearly as much warmth as a heater of similar wattage but also have the advantage of extra light. If your heat problems are during the plants night time use a standard heater instead but make sure any 'on' light is covered to stop it interrupting or interfering with the plants dark cycle. Simply raising plants off the ground on a table or pallets allowing a 'sink' for cold air will also help.
Extra Heating Outdoors.
Water in a good storer of heat so areas around large expanses of water are always a few degree`s warmer than inland areas. You can mimic this by placing water storage barrels near outdoor plots. Paint them matt black and they will warm up during the day and release their stored heat during the night, all for free.
Humidity.
The humidity is the amount of moisture in the air, the warmer the air the more moisture it can hold. In a hot grow room even of a modest size plants could be chucking litres of water into the air every day. This water laden air won`t effect growth directly but it needs to be extracted or vented out to avoid problems with moulds and fungus. Ventilate outside if possible as the moist air will condense on cooler inside walls causing damp like problems. Aim to keep humidity levels between 40 and 60% all the time as lower levels will also invite problems. These range from dry air loving pests like spider mites to a slowing down in CO 2 and light uptake if the atmosphere gets really dry.
Help Leaves Breathe.
Cannabis plants use the underside of their leaves to breathe. Fans blowing up from underneath plants will help them maintain adequate levels of CO 2 where they need it. They will also also help to keep down the humidity levels under the canopy.
(GFAQ)
A humidity and temperature gauge are essential in any growroom. Daytime conditions should be 70-80 degrees without co2, 80-90 degrees with co2 until the last two weeks when daytime temps should be kept between 70-80 and co2 can be reduced to adjust for the lower metabolism. Night temperatures should be kept above 60 degrees to prevent stress. It is preferrable during flowering to have a night temperature drop of 10-20 degrees to stimulate flowering hormones and reduce stem elongation.
I find that low humidity causes stress on plants. I recommend 50-60% humidity until the final 2 weeks of flowering. At this point, the humidity should be lowered as much as possible to encourage the plant to seal and protect itself with additional resin. (I am able to get the humidity to go as low as 31%) I have been able to frost things up considerably this way. The higher humidity levels prior to final ripening reduce salt levels within the plant tissue and encourage healthy, more lush growth.
MORE ON TEMPS AND HUMIDITY.
TEMPRATURE AND HUMIDITY GUIDE.
The Environment.
Air, temperature and humidity are closely linked and all are important factors in providing a good environment for your plants. Outdoor growers are at the mercy of the elements so control of the environment is limited for them, for indoor growers however things are different. Luckily the environment in your average heated house is close to the ideal conditions for cannabis growth. This makes indoor growing the best option in cooler climates like the UK.
Air.
Unlike us plants can`t move to get fresh air. When kept inside or in a greenhouse they can suffocate if the air around their leaves is not changed. During the night when plants are working on their roots and not producing any of their own oxygen the need for fresh air is even more important. To get the best from your plants therefore use circulating fans and ventilate or use extraction fans day and night.
CO 2.
Cannabis plants need to be able to extract Carbon dioxide (CO 2) from the air to use as a building material. The amount of CO 2 a plant can use depends directly on the amount of light it receives. Low light gardens (around 1000 lumens per sq. ft) will not be able to use any more CO 2 than is available naturally in the air. Higher light gardens can use more CO 2 but only if it is delivered in the right place, at the right time, at the right temperature and in the right amounts. Unless you have no fresh air ventilation at all or are a commercial grower CO 2 injection can be a lot of hassle and expense. It`s easier just to constantly pump in fresh CO 2 laden air.
Oxygen For Roots.
For healthy growth you need to make sure a plants roots have direct access to oxygen on a regular basis. In pots this means allowing the medium to dry out a bit between waterings. In hydroponics it means making sure you don`t saturate your medium too much. Flood and drain only once or twice a day or use NFT systems where most of the roots are out of the medium anyway. Healthy roots are bright white while roots starved of oxygen will start to go brown.
Temperature.
Cannabis can survive in temperatures ranging from freezing to 100 degrees but such extremes will slow growth and lower potency. For the best results during a plants day time keep temperatures between 70 and 85 degrees. At night aim for between 50 and 70 degrees. If heat becomes a problem try timing the light cycle to come on at cooler times like during the night. Using a thermometer with a min max setting will also make sure you are aware of temperature fluctuations that take place when you are not around.
Extra Heating Indoors.
Adding more HID lights is a good way to increase the temperature in a grow room. They kick out nearly as much warmth as a heater of similar wattage but also have the advantage of extra light. If your heat problems are during the plants night time use a standard heater instead but make sure any 'on' light is covered to stop it interrupting or interfering with the plants dark cycle. Simply raising plants off the ground on a table or pallets allowing a 'sink' for cold air will also help.
Extra Heating Outdoors.
Water in a good storer of heat so areas around large expanses of water are always a few degree`s warmer than inland areas. You can mimic this by placing water storage barrels near outdoor plots. Paint them matt black and they will warm up during the day and release their stored heat during the night, all for free.
Humidity.
The humidity is the amount of moisture in the air, the warmer the air the more moisture it can hold. In a hot grow room even of a modest size plants could be chucking litres of water into the air every day. This water laden air won`t effect growth directly but it needs to be extracted or vented out to avoid problems with moulds and fungus. Ventilate outside if possible as the moist air will condense on cooler inside walls causing damp like problems. Aim to keep humidity levels between 40 and 60% all the time as lower levels will also invite problems. These range from dry air loving pests like spider mites to a slowing down in CO 2 and light uptake if the atmosphere gets really dry.
Help Leaves Breathe.
Cannabis plants use the underside of their leaves to breathe. Fans blowing up from underneath plants will help them maintain adequate levels of CO 2 where they need it. They will also also help to keep down the humidity levels under the canopy.
(GFAQ)
doobieboy420
Member
LUDA...this post was alot of help to me and provided me with alot of informations thank you much +rep.
LUDA
New Member
Thank you.
doobieboy420
Member
no problem and thank you 
...im new to growing and appreciate all the help i can get
...im new to growing and appreciate all the help i can get
LUDA
New Member
Just ask buddy and i am sure i can help.no problem and thank you
doobieboy420
Member
same to you bud..if you have any questions i will help in anyway that i can even though im new to this.....smoked for a long time but never did a whole lot of indoor growing
LUDA
New Member
I have been soil growing for years mate. Thanks anyway.
doobieboy420
Member
no prob..just thought id offer lol even though you probly know 10 times more than me haha