Automated Air Exchange System

 By Rhizomorph

Nan's NookArchives : Grow Chambers : Projects : Humidifier tek



Holmes cool mist humidifier from Target $19.99
14' of 3/8" plastic tubing from O.S.H. $5
GLAD circular plastic container (3-pack) $4
4 Rubber bands - free
1 rubber gromet which she divided into 4 using scissors. (She used a Jerome Baker gromet... hey, she works in a headshop :-) )


Drilled 4 holes in bottom of one of the GLAD containers, evenly spaced. Used a 3/8" drill bit (to match your tubing).

Drill 2-4 additional holes in each glad container. This is to let some air escape. The diameter of the tubes alone is not sufficient to allow all the air being pushed by the fan through. This creates a back pressure which can stress out and shorten the life of your humidifier fan. Additional hole let the "extra" air out and take some stress off the motor. An air tight seal is not necessary - you will still get a very nice humid air stream through the tubes (you can feel it when you test it).

Cut Tube into 4 pieces.

Drilled a 3/8" hole in each terrarium for tube to go in. Drilled 4 smaller holes around bottom of each terrarium to allow stale air to leave.

Cut the edge off of the plastic container (the part the lid snaps on to) using a razor blade. This made taping it down a little easier.

Wrap 1 rubber band around each hose about 1" from the end.

Slide each hose through the lid until the rubber band stops it. Slip a gromet around each hose until it is flush with the container. Now the hose should be stable (you can't puch it in anymore, or pull it out). NOTE: She chose to use a bong gromet because she wasn't sure how moist it might get in there and she knows rubber bands will degrade quickly when wet - JB gromets get wet all the time and last forever. But having used it for a little while she hasn't noticed and moisture build up at all really, so rubber bands would probably do just fine for this part.

The GLAD containers she got fit *perfectly* around the top outlet of the humidifier (that's why she got them). Place on top and tape down with duct tape.

It is on a timer and set to run (along with the lights) for 1 hour every 3. That equates to 8 hours of light and about 8 fannings a day. She had PR pins that developed about 1 1/2 weeks ago. But due to minimal fanning (lack of time) and the PR's insatiable apetite for oxygen, the pins had stalled and weren't growing anymore. This was her solution. So I will definitely keep you guys posted on her progress.

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