What to do about really low humidity?

T

tilopa

Member

• Jun 19, 2020

• #1

I live in an area where the summers are hot, 100f+, and very dry. Currently my grow room is showing 20% humidity, with lights off. It's a little better at night as the humidity rises but with the AC running it lowers the humidity from what it is outside, so it is still in the 30s.

Wondering what to do about it. I've only seen those little walmart humidifiers, and not sure where I would put it in the room.

Anyone else have a low humidity problem, and what is your solution?

 

Midnight Tokar

Member

Veteran

• Jun 19, 2020

• #2

Check with UncleFishstick or his thread. He deals with ultra low humidity all the time, sometimes in single digits and he doesn't seem to have any issues.

 

troutman

Seed Whore

• Jun 19, 2020

• #3

Shallow trays filled with water and a fan blowing on them should help.

In the past, I have hung a moist towel in the room and kept wetting it as it dries.

 

Fixer

Active member

• Jun 19, 2020

• #4

If it's an option grow more plants. I thought I had a low RH issue until I got 24 plants growing in my veg room. Now I'm running a second dehumidifier.

 

Dropped Cat

Six Gummi Bears and Some Scotch

Veteran

• Jun 19, 2020

• #5

Fixer said:

If it's an option grow more plants. I thought I had a low RH issue until I got 24 plants growing in my veg room. Now I'm running a second dehumidifier.

Click to expand...

On point reply.

In case one is stuck with low plant count, a low rent method
is a clean water soaked, squeezed towel draped on a rod in the space.

 

MoS

Member

• Jun 19, 2020

• #6

If you can afford it, as you mention a humidifier, well worth the investment, and if possible place in on the floor or some sort of shelf eg. with a fan blowing behind it, if the space is there of course...

 

DrLongbottom

Well-known member

Veteran

• Jun 19, 2020

• #7

swamp cooler might be worth looking at

 

T

tilopa

Member

• Jun 20, 2020

• #8

Thanks for all those ideas.

I can't really fit anymore plants in the room. And it's pretty crowded in there to put a pan of water on the floor.

The hanging towel is an interesting idea. But then I would have to make sure to wet it when it is dry.

I think I have to shell out the money and buy one of those expensive ones that are connected to a continuous water source and mount it on the wall. And then in the winter I'll have to replace it for a dehumidifier. Indoor is a pain.

I've heard a few people say they have low humidity and it does not seem to bother the plants. But everything I've read says that too low is bad. The plant has to transpire more often and it could lead to nute toxicity, not to mention extra stress on the plant.

 

Mars Hydro Led

Grow on Earth Grow with Mars

Vendor

• Jun 20, 2020

• #9

a humidifier is the best way to go.

 

Fixer

Active member

• Jun 20, 2020

• #10

tilopa said:

Thanks for all those ideas.


I've heard a few people say they have low humidity and it does not seem to bother the plants. But everything I've read says that too low is bad. The plant has to transpire more often and it could lead to nute toxicity, not to mention extra stress on the plant.

Click to expand...

I often have my RH down in the low 50% range and it doesn't seem to bother the plants. You may need to adjust yours. I've attached a Vapor Pressure Deficit chart.

 

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L

Lightmeup209639

New member

• Jun 21, 2020

• #11

Anyone else have a low humidity problem, and what is your solution?[/quote]

Plant needs energy for growth, transport and maintenance of vital functions as animals do. To get the energy required, they oxidize (i.e. burn the photosynthetically fixed sugars). At the same time, water and carbon dioxide are released as waste products. Respiration occurs in all living plant parts (i.e. in the leaves, trunk and roots).
https://www.hiilipuu.fi/articles/plant-respiration
University of Helsinki.

 

L

Lightmeup209639

New member

• Jun 23, 2020

• #12

[FONT=Arial, Helvetica, sans-serif]Citrus sap by[/FONT][FONT=Arial, Helvetica, sans-serif]mellowfellow[/FONT]

 

K

kritios

Active member

• Jun 25, 2020

• #13

Could use a pebble tray. Use clean stones, and keep it topped up with water.



I found using a tray added about 10-15% to the ambient humidity in my tent.

 

Koondense

Well-known member

Veteran

• Jun 25, 2020

• #14

kritios said:

Could use a pebble tray. Use clean stones, and keep it topped up with water.

I found using a tray added about 10-15% to the ambient humidity in my tent.

[URL=https://www.icmag.com/ic/picture.php?albumid=82901&pictureid=2051338&thumb=1]View Image[/URL]

Click to expand...

Good advice!
Maybe add a ventilator on the side to increase the evaporation.

Cheers

 

moses wellfleet

Well-known member

Moderator

Veteran

• Jun 25, 2020

• #15

Wet wall/evaporative cooler, same concept as a swamp cooler. Water trickles through a cellulose pad, a fan draws air through the pad moistening it. It will also provide cooling as it humidifies the air, same way a human cools down by sweating.

This is the solution for commercial greenhouses but can be implemented on any scale.