Dehumidifiers (Desiccant or Compressor?)

[NorthofEngland]

During the last few weeks of my flower phase the RH could (and did) reach 90%
Especially during the dark cycle.
I had my 6"RUCK (working a 6"Rhino Carb Filter and cooling a 1000w HPS Power Station AeroWing Reflector) working on full power
and 2 x 16" fans blasting the air.
A third 16" fan seemed to help lower the RH by an average of 8%
Luckily my buds showed no sign of mould but I decided that a dehumidifier was needed.
This situation was in a 4 x 4 x 6ft tent.

I now have a 8 x 4 x 6ft tent.
Desiccant Dehumidifiers sound more effective - but are there reasons NOT to buy a Desiccant Dehumidifier?

Opinions will be appreciated.

 

[Spirallight]

I don't know. My dehumidifier is kept in the main room and I keep RH at 40% at all times. Inside the boxes I can now keep the RH at 30-40% I don't care if the humidity is too low I just don't want or need the issues associated with high humidity. I vent all my air into a separate room.

Hope that helps. You should be really careful to inspect for white powder mold which is imminent when the RH is above 80% for a day or two.

 

[NorthofEngland]

I don't know. My dehumidifier is kept in the main room and I keep RH at 40% at all times. Inside the boxes I can now keep the RH at 30-40% I don't care if the humidity is too low I just don't want or need the issues associated with high humidity. I vent all my air into a separate room.

Hope that helps. You should be really careful to inspect for white powder mold which is imminent when the RH is above 80% for a day or two.

The person who has just mentored me through my first grow told me that his RH never gets higher than 45% but the consensus of opinion seems to be high humidity for vegetative phase, low humidity for flowering phase.
Personally the black mould forming on my wall is enough to put me off wanting high humidity anywhere.

 

[GrowinDad]

It looks like one reason is that you would to replace the silica.

I have what I assume is a compresssor one. In the outer room as well. In the room i have a cab for veg and in it I run small humidifier. So I end up with humidity in there around 55, outer room around 40, and in the flower tent of around 45.

My outer room is very well insulated and the dehumidifier has provided the only heat I have needed in the room much of the winter.

 

[cloudsarehigh]

Hi!

If you can afford it I would say buy and run a copressor dehumidifier.

I know the general rule out there is to keep your humidity low... but, humidity in my closet never drops below 50% RH and it can be as high as 90% with temp. Range anywhere from 16 degrees Centigrade whith lights off to 25C lights on. I grow indoors mostly during the winter months. So those are some bad numbers, right...

Not necceserally... Ever since I took care of the air movement I had no more mold related issues, even with denser buds, such as NL.

I also use diy dessicant dehumidifiers (rock salt) its real cheap and it works, just dont expect too much, about 10-15% drop in RH is the most I get out of it.

So in my experience a generous air flow and movement is the key to avoiding mold problems. And its not that the fans lower RH, but rather that the molds thrive in stagnant air enviroment with high humidity, so by moving air around constantly you make their life just as difficult as with lowering RH. And its much easier to achive than lowering RH. Plus, the plants in a more humid enviroment transpire less, so you have to water them less, for me that is a good thing.

As you discovered for your self, with enough air movement you had no mold issues, so... If it works, dont fix it... It wont hurt though, to install a dehumidifier, its just an unnecessary expense in my view. Cheers.

 

[superstoner1]

The key to indoor growing is control, control of all aspects. The only way to have control over rh is a dehumidifier.