Humidity

NanoGadget said:

I flower at 55 to 60% and i have never had mold issues. Mainly its because i do most everything listed above.. lol. Lots of moving air, lights on at night etc.. i do have a nice sized dehumidifier just in case it gets out of control, but i havent even had to use my last two runs.

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hotrodharley said:

What Logan says plus run lights at night to help. It’s usually cheaper rates then too.

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InTheValley said:

its more humid at night,lol, so why run at night? it makes no dam difference, other then power is a tad cheaper.
As long as your not letting the plant cool to fast, even at 65% RH, u shouldnt see mold. keep temps at 80F if you cant get the RH out, and the fan constant,

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Cboat38 said:

I would like to flip my girls but this Michigan humidity is a little crazy I’m growing in a room but only using 4x4 of space it’s been over two months of veg they’re ready. Thing is I don’t a dehumidifier as of yet my temps right now is 85 and humidity 63 I know that’s too high for flower,and the humidity outside is even higher so question is how do I get my humidity down without dehumidifier until maybe a when I can by one

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• You can use a product called actinovate as a preventative (it works best that way).
• You want good air circulation 24/7. Stale "micro climates" like inside the lower parts of bigger plants with thick foliage will be the first places to show powdery mildew.
• Avoid letting the temperature drop when the lights are off as this will cause the humidity to spike since cool air can hold less water. A cool dark cycle with high humidity is often the trigger for powdery mildew.
• Avoid watering before lights out, this increases transpiration when the lights are off and evaporation is slowed.
• Any and all foliar applications, such as actinovate should be pH buffered to be slightly alkaline to avoid creating an environment conducive to mold and mildew. A pH of 7.5 - 8.0 is a nice safe space to be with foliar applications. It should also be noted that foliar applications should happen with plenty of airflow to aid evaporation. Unless a product specifically says do not apply when the lights are on you should apply with the lights on for humidities sake. The whole lens effect burning plants is a myth and if your plants are burning from a foliar application then you mixed up something too strong. It rains on plants all the time.
• Thinning out your plants with some defoliation is very helpful when you can't drop the humidity.
• Trying to maintain temperature and humidity balance according to a VPD chart has proven successful for some and not for others, I wonder if strain has something to do with that.

Renfro said:

Sorry if any of this is redundant. I am pretty stoned.

Of for starters, how do you cool your grow room? Are you ventilating it? If so then that will be drawing in humidity from wherever your intake air is coming from. So adding a dehumidifier wouldn't be able to keep up with the humid air coming into the room.

That leads me to the obvious solution, a sealed grow with AC and perhaps dehumidification.

In the meanwhile, to help prevent problems, aside from growing mold resistant strains here are some tips:

• You can use a product called actinovate as a preventative (it works best that way).
• You want good air circulation 24/7. Stale "micro climates" like inside the lower parts of bigger plants with thick foliage will be the first places to show powdery mildew.
• Avoid letting the temperature drop when the lights are off as this will cause the humidity to spike since cool air can hold less water. A cool dark cycle with high humidity is often the trigger for powdery mildew.
• Avoid watering before lights out, this increases transpiration when the lights are off and evaporation is slowed.
• Any and all foliar applications, such as actinovate should be pH buffered to be slightly alkaline to avoid creating an environment conducive to mold and mildew. A pH of 7.5 - 8.0 is a nice safe space to be with foliar applications. It should also be noted that foliar applications should happen with plenty of airflow to aid evaporation. Unless a product specifically says do not apply when the lights are on you should apply with the lights on for humidities sake. The whole lens effect burning plants is a myth and if your plants are burning from a foliar application then you mixed up something too strong. It rains on plants all the time.
• Thinning out your plants with some defoliation is very helpful when you can't drop the humidity.
• Trying to maintain temperature and humidity balance according to a VPD chart has proven successful for some and not for others, I wonder if strain has something to do with that.

View attachment 4403352

I hope all my rambling helps you get a successful harvest.

Click to expand...

Renfro said:

Sorry if any of this is redundant. I am pretty stoned.

Of for starters, how do you cool your grow room? Are you ventilating it? If so then that will be drawing in humidity from wherever your intake air is coming from. So adding a dehumidifier wouldn't be able to keep up with the humid air coming into the room.

That leads me to the obvious solution, a sealed grow with AC and perhaps dehumidification.

In the meanwhile, to help prevent problems, aside from growing mold resistant strains here are some tips:

• You can use a product called actinovate as a preventative (it works best that way).
• You want good air circulation 24/7. Stale "micro climates" like inside the lower parts of bigger plants with thick foliage will be the first places to show powdery mildew.
• Avoid letting the temperature drop when the lights are off as this will cause the humidity to spike since cool air can hold less water. A cool dark cycle with high humidity is often the trigger for powdery mildew.
• Avoid watering before lights out, this increases transpiration when the lights are off and evaporation is slowed.
• Any and all foliar applications, such as actinovate should be pH buffered to be slightly alkaline to avoid creating an environment conducive to mold and mildew. A pH of 7.5 - 8.0 is a nice safe space to be with foliar applications. It should also be noted that foliar applications should happen with plenty of airflow to aid evaporation. Unless a product specifically says do not apply when the lights are on you should apply with the lights on for humidities sake. The whole lens effect burning plants is a myth and if your plants are burning from a foliar application then you mixed up something too strong. It rains on plants all the time.
• Thinning out your plants with some defoliation is very helpful when you can't drop the humidity.
• Trying to maintain temperature and humidity balance according to a VPD chart has proven successful for some and not for others, I wonder if strain has something to do with that.

View attachment 4403352

I hope all my rambling helps you get a successful harvest.

Click to expand...