Grow mushrooms the EZ way.

Best Humidifiers for Growing Mushrooms

3 humidifiers lines up for comparison

TLDR (Too Long Didnt Read)

TLDRI’ve owned a few humidifiers for growing mushrooms, several of them have broken, one was not fit for purpose, however my latest one has been going strong for over a year. 

The best humidifiers for growing mushrooms:

  1. Vicks Cool Mist v600 – Pros: Name brand with good reputation, huge reservoir, does not require modification (if you follow my technique), availabe globally. Cons: Cost.
  2. HemingWeigh Ultrasonic Humidifier – Pros: 2.2L Large resevois, does not require modification (if you follow my technique), Dial ON button, Cost. Cons: Smaller Resevoir than Vicks.
  3. AquaOasis Cool Mist humidifier – Pros: 2.2L Large resevois, does not require modification (if you follow my technique), Dial ON button, Cost, Handle for easy carying and cleaning. Cons: Smaller than Vicks.

Main takeaways.

  • Beginners should really start with a spray bottle to get hands-on experience.
  • Buy a humidifier with a dial for the ON Switch! Don't Buy a humidifier with a button.
  • Tank size. The LARGER the better!
  • Name brand humidifiers cost more but last longer!
  • Don't modify your humidifier, buy one which a pipe can fit into it. This will last longer and not void the warranty (look at my setup section of this post).


Humidity is one of the primary variables you must control when growing mushrooms. Mushrooms on average are made up of 92% water and if you don't get the correct levels of humidity in your grow a whole myriad of issues can appear. 

Too little water and the mushroom substrate will dry out, too much water and the substrate will not produce a good pinset and could become contaminated due to pooling.

If you are searching “how to water mushrooms” then you are probably searching for the wrong information. Mushrooms are not watered per say in the same manner as plants.

When growing mushrooms the majority of the water for the growth is soaked into the substrate and is then absorbed up into the fruiting bodies as they are produced. Fruiting chambers are designed to cycle fresh air and humidity throughout the grow but sometimes the grow will require a top up.

However, it is still important to maintain high levels of humidity on the surfaces and environment in which the mushrooms grow. More often than not this involves a light misting of the substrate once or twice a day.

Growers use a range of different instruments and techniques to provide adequate humidity to their grows which I am going to cover in this article. 

Spray Bottles

Spray bottles are great for beginners, they are an affordable and effective way to increase humidity while cultivating mushrooms. 

I recommend getting a spray bottle which you can adjust the volume of the mist, this gives you better control over the amount of hydration you are providing to the mushrooms. 

This spray bottle here is the style I would buy, the end allows for fine adjustment of the mist. You can go all the way from a heavy stream to an ultra-fine mist, all of which can be useful for growing mushrooms. Dont get one like this or this.

The humble spray bottle could be all you need to provide the correct humidity levels within a fruiting chamber or grow. This is often how most mycologists start and gives them hands-on experience of judging and providing humidity themselves.

How Often Should You Spray Your Mushrooms?

Mushrooms are 90% water so it is crucial to ensure you are providing plenty of water for the mushrooms to absorb. 

In a monotub if there are small water droplets on the top of the substrate already then it is probably not worth spraying (misting) it. If the substrate has no water droplets on top then it is worth spraying once or twice a day. 

If I am growing mushrooms in buckets outside and there has been no rain recently I will go out in the morning and mist the bucket heavily until the bucket is wet. If I go outside and it is already wet or there is dew on the grass I will not mist the bucket at all.

This is  why it is recommended that newbies begin with a spray bottle to understand when a substrate is drying out vs perfectly hydrated. 

You want to be simulating a mushrooms natural fruiting environment so learn about how your mushrooms fruit in nature and try to recreate those conditions in the environment of your growth.

Ultrasonic Humidifiers

This is the typical “mushroom humidifier” you will see used in most home style grow setups.

Realistically most people are going to upgrade to an ultrasonic humidifier setup eventually, and why wouldn’t you?  

These humidifiers can provide airflow and humidity to mycelium substrate without you having to lift a finger.
Ultrasonic humidifiers use a small vibrating disc which creates tiny water droplets which are blown out of the device by a tiny fan creating a very light mist. 

They are often used in dry climates to help humidify rooms but we can use them to create fruiting conditions for fruiting!

You can literally automate mushroom growing using this type of humidifier and a digital timer if you know what you're doing. 

These humidifiers can be placed inside or outside the fruiting chamber. One of the advantages of channeling humidity in the fruiting chamber is that the humidity is introduced with fresh air, which helps to reduce carbon dioxide levels and improve the appearance of the fruits.

Personally, I have had more luck placing the humidifier outside my martha tent and piping the humidity and air in than placing the humidifier inside the tent. As shown in this post about making a martha tent here.

My Choices for Best Ultrasonic Humidifiers for Mushrooms:

1st. Vicks Cool Mist v600

This is my current humidifier and my favourite for the following reasons. Its pictured at the front of the top image.

Dial ON Switch – As discussed above this ensures that the humidifier works with an automated timer. Alongside this it means I can adjust the volume of humidity if I need more.

Tank Size – 4.1L This is a big tank for a home use humidifier, a tank this size can run for 30 hours before running dry.

Rotating Nozzle – This feature allows me to direct the coverage of the humidifier if I am using it outside of a humidity tent which I sometimes do. However it is also removable allowing you to fit a washing hose nozzle inside to vent it into a fruiting chamber.

Price – Not going to lie, it's on the more expensive side for a humidifier but it was worth it. It has outlasted all my other humidifiers and has the biggest tank!

HemingWeigh Ultrasonic Humidifier

I've owned this humidifier also and it was working great until i tried it inside my martha tent which broke it (definitely my fault). Its a great size for beginners and functional. Pictured to the right of the Vicks.

Dial ON switch

Tank Size – 2L is a good size tank and it can last up to 24 hours before it requires a change.

Rotating Nozzle – This feature allows me to direct the coverage of the humidifier if I am using it outside of a humidity tent which I sometimes do.

1 Year Warranty – This is self explanatory. 

Price – Cheaper than the Vicks but having bought both of them I definitely thought the Vicks was worth it. I got this one when money was tight then upgraded in due time.


3rd. AquaOasis Cool Mist humidifier

Dial ON switch

Tank Size – 2L is a good size tank and it can last up to 24 hours before it requires a change.

Rotating Nozzle – This feature allows me to direct the coverage of the humidifier if I am using it outside of a humidity tent which I sometimes do.

Simple to clean – This model provides a handle at top for carrying and holding the humidifier whilst cleaning.


What to Look Out For When buying an ultrasonic humidifier for growing mushrooms?

Dial ON Switch (no button).

The greatest mistake (one which I have made) is buying a humidifier which has a button instead of a dial for the ON  switch. Humidifiers with buttons are definitely NOT the best humidifiers for growing mushrooms.

If you want to automate your mushroom grows, do not make the same mistake I have made previously and buy a humidifier with a button. This will mean your automation dreams will not come into fruition. The button will still need to be pressed when the power comes on which means you have no automation at all!

Button humidifiers are definitely NOT the best humidifiers for growing mushrooms. DO NOT buy a humidifier with a button like this!

Finger pointing to button on humidifier

Tank size

Most likely you are going to want the largest tank size you can get for your money, this will ensure you are not running out of water and having to regularly change the tank.

Hole size

You want something with a big opening to fit a washing hose like this inside. This will prevent you from having to modify your humidifier voiding the warranty. 

When looking for a humidifier just check to ensure it is possible to remove the nozzle section on top so you can fit a piping tube inside. I get a universal washing hose like this then cut it down to size so it can fit.


Most humidifiers need regular cleaning so ensure that you purchase one which looks simple to maintain and clean.

My Humidifier setup for Growing Mushrooms

As discussed in my martha-tek post here I use the following setup to give my mushrooms automated fruiting conditions using an ultrasonic humidifier. 

I pipe a washing machine drain hose into the humidifier then pipe the other end into a martha tek tent. 

This creates 95%+ humidity in the tent whilst also adding fresh air. 

The washing drain hose fits perfectly into the Vicks humidifier ensuring no leakages without having to make modifications. I use a smart plug to schedule a time for the humidifier to turn on and off.

Vicks Cool Mist v600 – Discussed earlier in this post.

Smart Plug  – For scheduling on off periods of the humidifier.

Washing machine drain hose. This is a must have. You can cut the insert to size and push it into the hole for the humidifier (after removing the top plastic bit) which means there are no modifications needed which could void your warranty.

DIY Humidifiers

It is possible to make a humidifier yourself with a fogger and a container. Realistically though you will be creating the wheel here as most of these DIY builds are the same as ultrasonic humidifiers minus the warranty and electrical certificate. If you are a small scale hobbyist then it's probably easier to just stick to ultrasonic humidifiers.

However, Mushroom farmers often use the house of hydro fogger (a very large fogger with a good reputation) and a large bucket to create humidity in a large room. This kind of build is the only DIY humidifier I believe is worth your time building and is used for humidifying a full room:

House of hydro misting disc.

Large tote or bucket.

Computer fan.

PVC Pipe.

Large Humidifiers

Although I have never used this personally as my grows are not of the scale to require one (yet 😀 ), i have seen a many farmers on youtube using one of these. 

It has a whopping 42 litre tank, stands at 45cm tall and weighs 6.5 kilogram! 

The Ideal-Air humidifier contains an industrial-grade motor which can last for years of use, a multi-directional fogging head and can connect directly to your water supply!

It is sure to humidify a full mushroom grow room. I would definitely only get one of these if I had a commercial setup.

Ideal Air Humidifier

Wicking Humidifiers

These are not very popular amongst mushroom growers and probably not even suitable for mushroom growing. They may help marginally if you live in a very dry climate but really they are not worth it.

Wicking humidifiers are cold mist machines. They have a strip of material that draws water up through itself and past a fan naturally. 

The fan evaporates the water on the wick, which causes the internal reservoir to fill up with more water. These machines have the advantage of being self-limiting. 

The humidifier will be channeled into a fruiting chamber using PVC tubing connected to the unit outlet. 

These simple humidifiers function by wicking water from a reservoir and dispersing it over the surface. The water is then evaporated and the relative humidity of the air is increased by blowing air over the region with a fan.


Some people find using only a spray bottle is enough whilst other people are automation freaks and love building techy chambers its really down to personal preference when it comes to humidifiers for mushrooms.

Hopefully this analysis of has helped you make a descision on what you need.