[L'Emmerdeur]

 gavinsdankbud, on 04 June 2012 - 09:55 AM, said:

so why is every one on here say bigger extraction fan to low humidity and you say it will not work

Putting in a bigger extraction fan isn't the same as turning off your intake fan at lights off, which is what you advised...

 gavinsdankbud, on 03 June 2012 - 07:19 PM, said:

if the room not air tight have the intake fan on the light timer, so when the lights go out so does the intake fan
this will reduce humidity

...and which makes no sense at all.

[T-Rix]

Hi guys I did a little research into rh and bud rot, and came across some interesting information which I posted in my grow room build project:

 T-Rix, on 30 April 2012 - 08:11 PM, said:

OK – the last week of data from my logger:

Sauna-2012-04-23 to 2012-04-30.jpg

A few diary notes, as I wasn’t au fait with dew point before I started this project. Props to Wikipedia:

“The dew point is the temperature where the water vapour in a volume of humid air at a constant barometric pressure will condense into liquid water. Condensed water is called dew when it forms on a solid surface.

The dew point is a water-to-air saturation temperature. The dew point is associated with relative humidity. A high relative humidity indicates that the dew point is closer to the current air temperature. Relative humidity of 100% indicates the dew point is equal to the current temperature and that the air is maximally saturated with water. When the dew point remains constant and temperature increases, relative humidity decreases.”



Taken from Garden and Greenhouse dot net:

Tips for Conquering Mold in Your Grow Room:

By Tony Olissoff (Harvest Master)
Ever notice how badly some people suffer from mold and fungus in their growing areas and yet others seem to never fall into its grip? A climate control device can help you avoid the mold and fungus problems associated with many growing areas.

One of the greatest causes of mold and fungus is night time dew-point. The same effect you see when the evening dew in spring and autumn suddenly makes clothes wet on the wash-line, is the same thing that makes your plants gather moisture. It’s the fast falling temperature in the change from day to night where there is high humidity in a grow room. Once mold is in your room it’s very difficult to eliminate, so start with a clean growing are and with a plan to stay clean.

The best way to reduce the chance of this “dew-point effect” is to limit the temperature fall and potential condensation on to the cooler leaves of your plants. Using large fans to evacuate the air in your room, especially if cool night air is being drawn in, actually makes this condition worse. So you should use small fans that make slower changes to your room’s climate by lowering the humidity and temperature together, so that dew-point doesn’t occur.

Controllers limit the temperature fall into the night period, managing and monitoring the conditions to avert dew point, plant stress and to maximize crop strength.


Harvest Master , I would love to get to a stage where I could call myself Harvest Master!

Mr. T

Hope this helps a few people!

Mr. T