Microgrowers, how do you control humidity in a continuous grow?

Basic Growing Info
#1

I’m still really new to growing and I’m starting a continuous grow. I’ve got a flowering plant, some clones, and a seedling going:

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The flowering plant needs low humidity and since it’s a larger plant with more soil it produces more humidity. So I have a dehu in the room keeping the room at 40% RH which keeps the flower box around 45-50%.

Problem is, the other boxes are dry as hell (40%), and that’s a problem since young plants need humidity in the 60+% range.

In a tent situation I could probably put humidifiers or dehumidifiers inside the tents but in a micro situation that’s not feasible as far as I can tell.

What I’ve done so far is: in the starter box I laid out a wet towel under the plant, that seems to keep the humidity around 50% which is better but not great. In the veg box where there’s an exhaust fan pulling on it, I’ve put wet towels near the air intakes so the incoming air passes over the towels. This also keeps that box around 50% which is good but not great.

What can I do to improve my situation? Any advice is helpful. TIA.

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#2

Get a 1 gallon humidifier and an outdoor analogue timer, with 15 minute intervals, setup the timer to run 15 minutes every one to two hours. Adjust timer to dial-in your humidity. Both humidifier and timer are available on Am***n.

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#3

I would call @Mr.Sparkle for that question if it were me. :v:

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#4

My suggestion would be to do nothing.

You are close enough and I wouldn’t chase your tail over a few points. 40% is good enough.

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#5

Quick fix.
If you put ‘spacers’ under the pots in the dry zone (and assuming everything is dead level), you could have standing water in the tray w/o drowning the plants. That will give you the equivalent of the wet paper towel (or two…)

Cheers
G

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#6

My God man I had no idea there were such things as tiny desktop humidifiers. I found one that’s only 1L and 12cm by 12cm footprint. I’ve only ever seen the large old school kind that would be way too big for this box.

My controller board has a 24v circuit that I can use to drive a relay that will turn the humidifier on when the humidity drops too low and turn it off once it reaches the target humidity.

Solution in sight. Great tip, thank you very much!

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#7

the ultra sonic humidifiers do work and you can get usb pluggable ones to go super small but they wear out quickly.

My suggestion is turn off the room dehu and just run as is, or even raise your temps a bit higher temps allow higher humidity, and also in turn cause it as well due to plants transpiring.

also should have a circulation fans in each chamber just cause it helps even things out, pc fans and a 12v wall adapter from some old router or whatever works great for us micro growers.

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#8

Even hanging a wet washcloth in the corner could drastically raise the RH in such a tiny closet. You will probably need to re-wet it daily, but it’s an easy fix.

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#9

Yeah @firehead , that’s basically what I’m doing now, but it isn’t getting me enough humidity (gets me from 40% to 50% but for seedlings and new clones it’s best to reach 60%.

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#10

This is a good point. I had fans but they were too big for the space and took them out when I remodeled it, new fans are supposed to arrive today. With fans and creative placement of wet cloth maybe I can get where I need to go.

#11

Turn off big dehuey and let the room get to the 60%ish you need for veg, put one of these in the flower box controlled by a humidistat smart plug or Inkbird or something, you could even plumb that tank pretty easy into a drain hose for leaving it alone longer. I use this for the second half of drying my weed in an extra tent now running sealed after blowing off the big moisture at first with open vents for 4-7 days then basically cure in place with this, just had the best dry yet with it. They’re cheap, small, and reliable, quiet and don’t use much energy at all. Love me a Peltier cooler

I mean shoot if that’s too big at 10.5 x 6.5 x 5” there’s this cool one that uses desiccant to scarf 6-8 oz of water from the air then you plug it in to recharge/dry it:

2 Likes
#12

That’s very interesting @Dirt_Wizard! Thank you for sharing that!

The air in my flower box changes over fairly often, do you think that little dehu is sufficient to keep up?

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#13

Well, it says the Eva-Dry removes 8 oz of water per 24 hours so that’s 0.33 oz/hr. My head is not working well enough right now but when I can do the math I’ll check how well it could keep up theoretically

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#14

A 5 gallon bucket of rock salt with dehuey a small area also.

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#15

Woah I just realized that with a dehu in the box I can lower my exhaust fan speed tremendously (I keep it cranked to keep humidity down) so that means the air turnover in the box is lower which means the dehu shouldn’t have any problem keeping up.

Wow I’m really digging this solution. This is a great plan, at least in concept. Thanks so much for jumping into this thread.

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#16

Wow I just realized that this little thing runs on 5V DC which means that (using an adapter) I can plug it directly into a motor port on my SGL controller which will switch it on/off based on the humidity sensor. I can literally configure it right in the app. This is an amazing plan, I gotta try it. Thanks again!

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#17

Oh yeah! You can! I didn’t even think about the 5V DC power and compatibility with your controller but that makes a lot of sense, people seem to like these for mobile homes and I think a lot of climate and other mechanical stuff in there is all controlled centrally nowadays via 5VDC or 12VDC power from the battery banks. Very cool! I will remember that myself for the future I wonder if it plays nice with the grow controller systems in general as a plug and play device….

I bought it because they’re well reviewed and seem to be the one that gets knocked off endlessly, and because it’s so dumb it won’t mess with my external Inkbird control, but that’s more elegant.

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#18

Heads up I just looked and it’s 9V DC:

EDV-1100 Dehumidifier Specifications:

  • Moisture removal: 8 oz/day (at 86°F; relative humidity 80%)
  • Water tank capacity: 16 oz.
  • Peltier technology/no compressor
  • Power: 22.5W
  • Adaptor Output Voltage: 9V DC; 2.5 Amp
  • Input Voltage: AC 100-240V, 50/60Hz
  • Weight 2 lbs/0.9 kgs
  • Product size: 11″H x 6.5″W x 5″D
#19

i have one of the petites. i didn’t think it did much. maybe 1% absolute change in a 2x4x5.

@Beak I just separate the hvac. i have rh controllers inline with the temp controllers on each tent with separate flows to outside .you only need the lung room rh to be low enough for the flower room or lowest rh room. the other tent will use the rh controller to keep from intaking unneeded low rh air…if you are running super hot you will have lower humidity, but that works with vpd. or, just use 2 separate rooms or use a garage for one tent/box.

#20

Oh bummer, looks like I got a knockoff :roll_eyes:

I’m in Europe, that brand isn’t readily available.

Well I can try it for a day and see what it does. If it works, great, if not, back it goes.

1 Like