Monotubs

The Monotub is a tool that most indoor mushroom cultivators use to start growing. It's an easy and fast way to cultivate mushrooms and it doesn't take up much space or require investment in expensive humidity or ventilation systems. The construction is pretty straight forward and quite simple to make , most are made from plastic bins or are inflatable or even pop up framed. The plastic tubs have various holes , generally different sizes that are covered by filters to allow the passage of air but bring in no micro organisms in to the tub. This helps to maintain an ambient humidity levels for pinning , fruiting and maximum colonization. 

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The monotub is used to grow various strains of mushrooms. Depending on what you want the  mushrooms for whether it be to eat , study or in countries where allowed magic mushrooms. The method in growing is similar across all varieties. Usually a layer of coir substrate then your rye or corn then another coat of substrate. Psilocybin seems to really like this method and it is reported great success.

Manure , hardwood substrate and wood chips also work well in monotubs with the mushrooms that prefer these.

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It is worth giving it a try as the yields can be a lot greater than using growbags alone. As you can see their are different types of monotubs around , you can see on the two inflatable tubs that the first layer in blacked out , this is to promote the pins to grow upwards towards the light rather than just growing out.

With the hard plastic tubs , bottom liners are available that will cover the bottom of the tub and up the sides to help with upward growth. 

If making your own a few layers of gaffer tape on the outside of the tub works just aswell but dont forget the underside of the tub. 

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Dont forget to thoroughly clean out the tub before use and use 70% isopropyl to wipe around the inside and the inside of the lid.

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What you need to make your own tub.

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1 Spore syringe or a liquid culture syringe
2 Injection port bag ,mason jar fully colonised or a colonised grain spawn
3 Ready made monotub
4 black bag (if your own monotub you can use a black binbag)
5 Self-adhesive monotub filters ( 25cm and 50mm )
6 Hand drill with a small drill bit for pilot holes
7 2 hole saw bits, both 25mm and 50mm
8 Blade for cleaning hole edges
9 Measuring tape
9 A sharpy
10 70% rubbing alcohol (Isopropyl alcohol)
11 Rubber gloves
12 Two spray bottles (one for alcohol and one for water)
13 Bulk substrate , CVG , Coconut coir , hard wood chips , manure
14 Still air box or laminar flow hood to inoculate in a clean environment

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Make your monotub

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There are many ways and materials you can use to make a monotub. Most frequently large plastic containers are used. Though we used two sizes of holes for our build, there is flexibility with hole placement and size depending on which species you're going to be growing in your tub. We designed our tub with flexibility and airflow optimization in mind for growing the widest range of mushroom species. But for growing one certain variety of medicinal mushroom you can get away with just the two inch holes.

You will be drilling a total of six 50mm holes around the perimeter of your tub: two holes on each long side and one hole on each end about150mm from the base of the tub. Then, you will drill 25mm holes positioned approximately 110mm from the base. Ideally, the smaller holes should be just above the top of your substrate. The bin we used is roughly 500mm, so our 25mm holes are positioned at 125mm, 250mm, and 375mm across.

Start by measuring out and marking where your holes will be. Then, use the drill and small bit to drill pilot holes in the centers to avoid cracking.

Using your 25mm and 50mm hole saw bits, create the holes, being sure to drill in reverse. Drilling forward rips at the plastic and can cause cracking, while reverse is easier and melts the plastic (drilling in a well-ventilated area and wearing a mask are not bad ideas!).

Finally, clean up the rough plastic edges of the holes using your knife.

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Incubation

A common misconception is that mycelium and mushrooms in general prefer to grow in the dark. They don't. In the wild mushrooms tend to fruit in darker, shaded areas due to higher levels of humidity. In fact, ambient light plays an important role informing the fungus where to fruit, it's necessary for the production of certain natural chemicals within the fungus, and aids in color and fruit body formation.

With that in mind, the environment in which you're growing your mushrooms plays a big role in the success of your grow. It's best practice to store your tub away from direct sunlight and in a temperature controlled room between 65 and 75° F. An area that's too hot will dry out your mycelium and promote contamination, an area that's too cold will slow the colonization process down significantly, if not completely. Your tub should take around 2 to 3 weeks to fully colonize.

Check on your bin daily. You'll see white spots start to expand from each point of grain spawn. Over time they will completely cover the surface of the bulk substrate. You should see small droplets of mushroom exudate. This is natural and a sign of proper hydration and a speedy colonization. You want to look for the signs of pinning mushrooms. This usually looks like white hyphae growing vertically from the surface of the substrate and forming little knots of dense white mycelium. Tubs will take 2-3 weeks to fully colonize for most dung loving species. Wood loving species colonization rates will vary.

When your tub is fully colonized, you may notice some condensation on both the lid and the substrate, which is a good sign that your tub is properly hydrated. You might also see droplets of amber colored liquid called exudate on the substrate, this is a normal byproduct of fungal metabolism. Coloration of mycelium varies species to species, with some mycelium even turning slightly blue over time.