Quote:

Note that these are commonly called a number of different things, most commonly a "cool mist." This can be misleading as sometimes ultrasonics are labelled as "cool mist." Check to make sure your humidifier uses a filter before purchasing.

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The ultrasonic is a $60 ultrasonic, also from a department store during winter months.  It holds 1.25 gallons of water (I believe).

I bought these with no particular specifics in mind, the only thing you should consider is how often you want to fill them (capacity) and if they fit in your GH (very important.)  Just stay away from foggers meant for reptile terrariums and other small or low-capacity ultrasonics, you'll be filling them constantly.



It's very easy to overthink a greenhouse. Here's the adjustable variables as I see them:

Humidity (surface): Each substrate in the greenhouse gets cased to provide a nice microclimate of 99% RH at the surface of the substrate where it matters. The ultrasonic provides a "misting" by running 15 minutes on every 1-2 hours. This keeps the casing layer moist but never wet.

Humidity (environment): An evaporative humidifier is used to buffer the RH levels inside the GH.  My humidifier in my environment keeps the RH level at a minimum of 85%. Every one hour the ultrasonic is on for 15 minutes and the RH jumps up for a bit.

FAE: As much as possible. I run my evaporative humidifer 24/7 for my edibles that don't mind a bit lower RH in the chamber. For cubes I have been finding my casing layers dry up too quickly. To compensate, the cool mist is on 30 min then off for 30. The ultrasonic runs 15 min on every hour, right after the cool mist shuts off You can adjust the amount of FAE by how zipped/unzipped the curtain is on the sides.



Here's how it is set up, it's very simple:

Two 4-tier wire shelves back to back. Ultrasonic on the top, evaporative humidifier on the bottom corner. Curtains unzipped 1/4 of the way on both sides.



Curtains pulled back by the evaporative humidifer for good FAE.



Timer for the ultrasonic is 15 minutes on every one-two hours.



I use only distilled water in the ultrasonic. This way I never need to worry about scaling and buildup ruining the fogger disc.

The scaling on the evaporative humidifer gets cleaned once a month with vinegar, a good soak and scrubbing will break all those mineral deposits off. The filter/wick gets washed off every two weeks and changed every month or two.

Other than filling the humidifiers, it is pretty much set-n-forget.



I have messed with a few different GH setups in the past, here's that shit I don't like:

1) Impellers. These fucking things never failed to soak my GH, no matter how many slits or timings I tried. Too much wet, too loud, too much maintenance.

2) Computer fans. I know they work for a lot of people but I want TONS of FAE in my GH.  Even larger computer fans have never satisfied me.

3) Hygrotherm. It's a cheap humidity/temp controller intended for reptile terrariums.  Precision humidity control may have its perks, but the humidity I care about is at the surface of the substrate. It was a waste of $90.

4) Slits. I don't like cutting up my GH

5) Piping in the humidifiers from the outside. I've found it unnecessary and a pain in the ass.


Cubensis, WBS bag:


P. Galindoi:




King oyster:



There are a million ways to dial this in for different species, but I am sticking to the basics because more specific greenhouse methods are something you will need to figure out given your specific environment and conditions.

Saint Stephen said:

How small can a green house be and still be work? My pmp is running out of room. i was hoping to use maybe 3 tiers of shelves?

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You can scale it down. You just need to adjust your ultrasonic timings accordingly so you don't flood your GH

cronicr said:

all thats missing are the mushrooms;)

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FrankHorrigan said:

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Link is in the OP

I don't have any recent active grows in the GH. It's kept in a cold room for kings most of the year and I didn't figure many folks here would find that as interesting as they do over in GMM

veda_sticks said:

And because your using a casing layer its more tolerent of lower RH plus having an ultrasonic come on its keeping effectivly misting the casing layer and the water that evaporates from the casing layer is also helping to contribute to humidity?

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Pretty much, yeah

By itself the wick type humidifier will not provide humidity higher than 86% IME. It really does work great to disperse the moisture from the ultrasonic around though.

So the wick type humidifier is really just for constant FAE + maintaining a certain minimum RH for the environment. The ultrasonic takes care of the rest.

If you don't want to case your trays, then it's just a matter of adjusting your ultrasonic timings to make sure the substrate doesn't dry up too fast.  If you really wanted to get fancy you can put the cool mist on a timer as well, but I love my 24/7 FAE

I prefer casing them for the GH as well.

FrankHorrigan said:

veda_sticks said:

And because your using a casing layer its more tolerent of lower RH plus having an ultrasonic come on its keeping effectivly misting the casing layer and the water that evaporates from the casing layer is also helping to contribute to humidity?

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Pretty much, yeah

By itself the wick type humidifier will not provide humidity higher than 86% IME. It really does work great to disperse the moisture from the ultrasonic around though.

So the wick type humidifier is really just for constant FAE + maintaining a certain minimum RH for the environment. The ultrasonic takes care of the rest.

If you don't want to case your trays, then it's just a matter of adjusting your ultrasonic timings to make sure the substrate doesn't dry up too fast.  If you really wanted to get fancy you can put the cool mist on a timer as well, but I love my 24/7 FAE

I prefer casing them for the GH as well.

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Quote:

1) Impellers. These fucking things never failed to soak my GH, no matter how many slits or timings I tried. Too much wet, too loud, too much maintenance.

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I've had two different v400s.

I hated them both.

Yeah, no impellers for me

llama_police said:

What is your room temp? I am still trying to dial in a GH and I'm getting stupid amounts of condensation, resulting in poor RH, so I'm wondering if it's because I am keeping it my garage, which is dropping to around 12-15c at nights at the moment and only getting to around 18-20c by day. I have a fishtank heater + airstone in a big tub at the bottom of the GH and have just lowered the temp in that to about 22c, which seems to have helped a little. However the RH is still sitting down near 75%. I have a fan blowing fresh air in for 15 mins every hour and an ultrasonic in the top, running for 4 minutes every 2 hours. Should I increase the ultrasonic increments?

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Maya Boomba said:

Hey Frank! A question not related to this thread but I know it's the best way to get a hold of you. How do you dry your fruits? I'm currently just fanning them but i'd like to know a better way if I was planning to do more tubs in the future.

Do you use Damprid? I'm trying to find a store where I could buy wtv works best to dry them.

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Use a dehydrator.

Next time send me a PM instead of jacking the thread

cronicr said:

for me it was always having beads of moisture on the surface but not pooling

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cronicr said:

for me it was always having beads of moisture on the surface but not pooling

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When it's cased you want to make sure your casing layer is always moist, never wet or dry though.

the_jerk said:

Frank, I noticed you're advocating for wire shelves. How much of an issue has rust been?

I have a plastic height-adjustable 5-shelf unit (18"x32") wrapped in 6mil plastic and I'm working on dialing it in empty. I know this will change a bit when full, but will give me a good baseline.

My vicks cool-mist (impeller type) is keeping it at 93-95% (measured in the center of the middle shelf) pulling in fresh air at the bottom corner like yours is. A lot of that moisture is condensing on the underside of the first shelf above the humidifier and raining back down. This led me to think the plastic shelves dont have enough negative space in them....although they appear to be about 50% holes, 50% solid.

I also tried plumbing in a very good ultrasonic I have from the outside, into the center shelf but it too seems to just fall to the floor after completely fogging out the center .  Keeping the top two shelves adequately humidified seems to be my issue.

Any advice based on the above? Perhaps I should re-purpose the plastic shelves and switch to wire. I cant find martha's or mini GH's at stores near me so I'll be making mine from shelves and a plastic sheet. This at least gives me the ability to use any shelves. I'd like to keep the dimensions within 19" x 42" x 8'

As always, I appreciate your input and knowledge. I recently switched back to using a TiT incubator like everyone used to back in the day after reading your write up and I cant believe I ever stopped. The difference is significant, even over a temp-controlled room

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I recommend (and bear with me here) ditching the impeller.

IME impellers make things very wet and its difficult to not soak everything.  I swapped my impeller with a cool mist and ultrasonic (neither piped in) and never looked back.

The buffered RH FAE allows great evaporation in between ultrasonic "mistings" so the casings /subs never dry out before the first flush is over and it needs to be re-cased anyhow.

Rust has not been an issue with my wire shelves, I've done about 6 months of runs on these new shelves and all is well. I even double checked today.

I hope this helps!

FrankHorrigan said:

I recommend (and bear with me here) ditching the impeller.

IME impellers make things very wet and its difficult to not soak everything.  I swapped my impeller with a cool mist and ultrasonic (neither piped in) and never looked back.

The buffered RH FAE allows great evaporation in between ultrasonic "mistings" so the casings /subs never dry out before the first flush is over and it needs to be re-cased anyhow.

Rust has not been an issue with my wire shelves, I've done about 6 months of runs on these new shelves and all is well. I even double checked today.

I hope this helps!

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I knew the line about ditching the impeller style humidifier was coming Since it's what I have I will turn it down to low to try and mimic the rate of a cool mist wick-type. I toyed with the low setting over the weekend and it seems to not be soaking everything anymore. I'm stopping by a cigar shop today to pick up a new hygrometer to double check the humidity. My digi says 94% and my analog one - calibrated with the wet paper towel - reads 95-97% hard to tell exactly and that's just with the cool-mist running on low. Since it's on low I have a little fan pushing air up from beside the cool-mist to helop circulate stale-air.

I'm glad to hear you haven't encountered rust issues. I had read some posts, one by RR, where they had terribly rusted shelves within a week. That's why I went plastic and chose the shelves with the most amount of ventilation holes in them. However, the wire shelves offer at least triple the hole-space as compared to plastic. I'd like to try 360 degree fruiting from some cakes from small trays which would require wire shelves. All my mono's seem to want to fruit 360^o anyways.

I was going to build a PVC frame to hold the plastic sheeting around the shelves...then I came acrioss corrugated plastic sheets:


Can you think of any reason for me to NOT make the sides, back, and top of my greenhouse out of a clear version of this material instead of plastic sheets on a frame? I think it would be easier to work with and doesnt require a frame to hold it up. Only the front "door" with zipper would be 6mil plastic sheeting.

Sorry for all the questions, if you think I should just start a thread instead just say the word. I just thought maybe this discussion might help others referring to your tek's (like I do all the time) that cant find mini greenhouses in stores anywhere, like me.

FrankHorrigan said:

FAE: As much as possible. For low-RH tolerant species: With the filter/wick-type cool mist buffering the RH, you can and should run your cool mist 24/7.  This provides a ton of FAE. You can adjust the amount of FAE by how zipped/unzipped the curtain is on the sides. For cubes: I have been finding my casing layers dry up too quickly. To compensate, the cool mist is on 30 min then off for 30. The ultrasonic runs 15 min on every hour, right after the cool mist shuts off

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updated the OP, been playing with cubes in here again

FrankHorrigan said:

Now that it is warm in my basement I will be messing with cubes in here.

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Small update.

That's a bag of WBS spawn intended for a tub that had a pea-sized spot of bluing myc on it. So I cased it with 50/50+ and fruited it in the greenhouse. Looks like a leucistic in the middle there

cyb3rtr0n said:

You mention using two greenhouse shelves back to back.  Do you cut the backs out of each greenhouse plastic and seal them together or something?

I'm thinking of a mini greenhouse setup, would adding a cool mist and an ultrasonic on a cycle timer take up too much room if only one GH is used?

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FrankHorrigan said:

Some people "pipe-in" their humidifiers to save space and evenly distribute moisture and air. I think it's over complicating things.

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FrankHorrigan said:

P. Galindoi:


King oyster:

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SpawnRun said:

And for the record, impeller humidifiers ARE cool mist humidifiers.....

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FrankHorrigan said:

I use an ultrasonic humidifier and a filter/wick-type cool mist humidifier.

It's a $35 cool mist (wicking/filter) bought from a department store during winter months.  It holds 1 gallon of water and it has a low and high setting. I use the low setting.

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joeydimes said:

Frank,

I see your trays are aluminum containers lined with garbage bags. Now do you cover those before fruiting after you add the spawn and substrate mixture together to let them consolidate?

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SpawnRun said:

I thought you were distinguishing between impeller humidifiers and coolmist humidifiers.  Nice grow, BTW....

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Gotcha, no, just for simplicity sake I was referring to impeller CMs as impellers and wicking/filter CMs as cool mist. I hate having to distinguish between the two every time the phrase comes up.

golden myc said:

I guess the cool mist blows the trich everywhere....

I wonder if I had cased, if this would have happened..

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I mean, it blows the spores everywhere, but if you have properly pasteurized substrate and clean grain spawn it will not be a problem.

Casing shouldn't matter if the casing layer and sub are properly pasteurized and the spawn is clean.

Sorry for your loss

FrankHorrigan said:

golden myc said:

I guess the cool mist blows the trich everywhere....

I wonder if I had cased, if this would have happened..

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I mean, it blows the spores everywhere, but if you have properly pasteurized substrate and clean grain spawn it will not be a problem.

Casing shouldn't matter if the casing layer and sub are properly pasteurized and the spawn is clean.

Sorry for your loss

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FrankHorrigan said:

cyb3rtr0n said:

You mention using two greenhouse shelves back to back.  Do you cut the backs out of each greenhouse plastic and seal them together or something?

I'm thinking of a mini greenhouse setup, would adding a cool mist and an ultrasonic on a cycle timer take up too much room if only one GH is used?

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No, no, it's not GH shelves, they are actual 4-tier wire shelves.

The tarp is from a large (double-wide) mini-GH found at a garden store.

You can do this with one set of shelves or two.  Use the same equipment for either.

Some people "pipe-in" their humidifiers to save space and evenly distribute moisture and air. I think it's over complicating things.

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tbagtag said:

Frank, how necessary is the casing layer for a greenhouse?  I just set mine up and wont have anything to stick in it for 4 days.  I plan on going a very low tek route.
If I need a casing layer what would you recommend?

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I would go with 50/50+ but if you are going low tek, verm will work as well.

Or even just straight coir if you wanna get real old-school



Updates, everyone, nothing major but I realized I had some very early galindoi images up. I replaced them with the galindois at harvest time. Much better