Cab Grow, Dense Canopy, Powdery Mildew And Air Movement

[Kalikush]

My next grow will have to be in a cab unfortunately and the last time I did this, I ended up with PM. I see lots of people growing similar to my last grow, ( see the pic) but not having PM issues. I don't remember having high humidity. It's generally not humid here, I was using A/C in the room to keep temps down and I was using a 4" inline fan that was exhausting the cab properly. I had some computer fans also but still ended up with PM.

If needed, I plan to use a "damp rid filter" along with a hepa filter on the intake to help keep humidity down. I have a 6" inline that should easily provide adequate turnover and will see if I can mount some small oscillating fans as well. My cab will probably be 2' x 3' and I'd like to have a SCROG setup again. Am I missing something here? What else can I do to ensure I don't get PM again this time around?

 

[GT21]

My next grow will have to be in a cab unfortunately and the last time I did this, I ended up with PM. I see lots of people growing similar to my last grow, ( see the pic) but not having PM issues. I don't remember having high humidity. It's generally not humid here, I was using A/C in the room to keep temps down and I was using a 4" inline fan that was exhausting the cab properly. I had some computer fans also but still ended up with PM.

If needed, I plan to use a "damp rid filter" along with a hepa filter on the intake to help keep humidity down. I have a 6" inline that should easily provide adequate turnover and will see if I can mount some small oscillating fans as well. My cab will probably be 2' x 3' and I'd like to have a SCROG setup again. Am I missing something here? What else can I do to ensure I don't get PM again this time around?

Youre just missing more air exchange. .. not like movin air around in the cab but more pulling the air out of the box and replacing. Air exchange is your friend when it comes to heat and humidity

 

[Kalikush]

Youre just missing more air exchange. .. not like movin air around in the cab but more pulling the air out of the box and replacing. Air exchange is your friend when it comes to heat and humidity

I'm sure I had a lot of air exchange, it was a small cab, probably 2'x4'footprint, about 3' tall and the 4" inline sounded like a jet engine before I installed the muffler. I know that and the scrubber reduce airflow but there was still a good amount of air being pumped out of there. Obviously this could have been it which is why I'm trying to figure out if oscillating fans will prevent this from happening again so long as the humidity and temp is kept in check. I do have a 6" inline this time but need to figure out how to get airflow into the middle of a dense canopy. I'll probably trim more of the smaller branches this time also to thin the canopy a bit.

 

[GT21]

I'm sure I had a lot of air exchange, it was a small cab, probably 2'x4'footprint, about 3' tall and the 4" inline sounded like a jet engine before I installed the muffler. I know that and the scrubber reduce airflow but there was still a good amount of air being pumped out of there. Obviously this could have been it which is why I'm trying to figure out if oscillating fans will prevent this from happening again so long as the humidity and temp is kept in check. I do have a 6" inline this time but need to figure out how to get airflow into the middle of a dense canopy. I'll probably trim more of the smaller branches this time also to thin the canopy a bit.

Well i do sogs in a 5x5x7 area and never have that problem and my canopy is that dense. I use a 450cfm and no internal fans... just suction.. i just pump all the air out of the tent and dump it into the next room.... cleaning up the bottom branches helps a ton too

 

[3N1GM4]

Powdery mildew is actually caused by a few different types of spore producing fungus. It reproduces by shooting out spores and the spores float through the air and deposit on your plants and start reproducing.
If you keep getting it I would say you probably didnt clean good enough after the last outbreak or there is powdery mildew outside your cab somewhere and your fresh air intake is sucking in spores and they are depositing on your plants every new grow.
I would suggest cleaning really well with bleach water and adding a filter to your intake might help too.

 

[Kalikush]

Well i do sogs in a 5x5x7 area and never have that problem and my canopy is that dense. I use a 450cfm and no internal fans... just suction.. i just pump all the air out of the tent and dump it into the next room.... cleaning up the bottom branches helps a ton too

I've got the same size fan (6" Can Fan) but only a 2x4x7 area. It probably won't run at 100% and I will have a muffler, scrubber and one right turn. I'll work out the numbers but I hope that will be enough. Might have to go to 100% if not..

Powdery mildew is actually caused by a few different types of spore producing fungus. It reproduces by shooting out spores and the spores float through the air and deposit on your plants and start reproducing.
If you keep getting it I would say you probably didnt clean good enough after the last outbreak or there is powdery mildew outside your cab somewhere and your fresh air intake is sucking in spores and they are depositing on your plants every new grow.
I would suggest cleaning really well with bleach water and adding a filter to your intake might help too.

Funny thing is, when I got PM, that was the first grow at that house and everything was new to begin with. I was looking into putting a hepa filter on the intake this time though.

 

[GT21]

I've got the same size fan (6" Can Fan) but only a 2x4x7 area. It probably won't run at 100% and I will have a muffler, scrubber and one right turn. I'll work out the numbers but I hope that will be enough. Might have to go to 100% if not..



Funny thing is, when I got PM, that was the first grow at that house and everything was new to begin with. I was looking into putting a hepa filter on the intake this time though.

You might want to add uvb to your grow too... pm hates those lights.

 

[Kalikush]

You might want to add uvb to your grow too... pm hates those lights.

I'll have a look into that too, thanks for the tip. I will have my eye out for it from the beginning this time too so hopefully I can just create an environment inhospitable to PM in the first place. I plan on doing weekly preventative organic pest sprays too so I might see if the neem or something else will help prevent PM.

 

[ArcticOrange]

One thing you have missed is temp and rh swings between day and night. Does your therm and hygrometer have a day night high low? That could be a contributing factor.

 

[Kalikush]

One thing you have missed is temp and rh swings between day and night. Does your therm and hygrometer have a day night high low? That could be a contributing factor.

I'm not up and running yet but was planning on getting a weather monitoring system that will be able to tell me day/night highs/lows and I will keep watch this closely. Good tip, thanks

 

[Kalikush]

I just don't get how growers like this are able to keep PM out of the middle of their rooms in setups like this. It appears that there is no access to the center and fans are only along the perimeter. If they have a huge exhaust fan, will that get enough air movement in the middle or if it's sealed, is just keeping temps and humidity in check enough? I'm assuming they have filters on intakes to prevent spores coming in that way.

 

[GT21]

I just don't get how growers like this are able to keep PM out of the middle of their rooms in setups like this. It appears that there is no access to the center and fans are only along the perimeter. If they have a huge exhaust fan, will that get enough air movement in the middle or if it's sealed, is just keeping temps and humidity in check enough? I'm assuming they have filters on intakes to prevent spores coming in that way.

Many use chemicals for preventative maintenance... as you can see with all the medicine recalls going on right now. Others go way over board on ventilation which is a good thing... then some of the rooms are gassed

 

[Kalikush]

Many use chemicals for preventative maintenance... as you can see with all the medicine recalls going on right now. Others go way over board on ventilation which is a good thing... then some of the rooms are gassed

I guess that's what I'm forgetting, the chemicals. I really want to not have to use these so I'm going to try giving each cola about a square foot for each so I can maintain good airflow all around. I have a bit more headroom this time so I'll just grow taller instead of short with many many tops. I forget what bacteria I read about helping to prevent PM with foliar sprays but I'll look that up and treat in veg with that too.

By gassed do you mean sulphur?

 

[MidwestToker]

I change my air in my 4x4x7 every 1.5 minutes.

 

[Dr.Trichome]

Actinovate, that's the stuff for Pm/mold. It eats it up. Works great. All natural, no chems.