Why us a Still Air Box (SAB)?
One of the most important things in cultivating mushrooms is working in a clean environment. Mushrooms are fragile and very susceptible to contamination, working inside a SAB drastically increases the chances of your mycelium growing healthy and without contamination. 

Still Air Box (SAB)

How does it work ?
There are millions of particles floating around in the air we breath, from bacteria to other fungal spores that would compete with your mycelium. When working inside a still air box as in the name the air inside is still, this still air creates a barrier to harmful particles that are floating in the air around you. As these particles move into still air they quickly loose their velocity and fall to the ground. Your still air box does not need to be sterile just clean and still.

What is a glove box ?
A glove box is simply a still air box that have gloves sealed the the holes where your hands go inside. They are more difficult to make, more difficult to use as your hands are in thick gloves and some people say they do not work as well as a still air box.

What is a Laminar Flow Hood (LFH) ?
A LFH is a sealed box with a fan on one side that pushes air through a HEPA filter. This filters out 99.93 % of particles in the air that is blowing out through the filter. When working in front of this clean air it you can do what you need to with the assurance that most possible contaminates have been filtered out. The pros of a LMF is that it is much easier and quicker to work with and more reliable. However they are expensive and for home growers a still air box lets you do anything that a LFH will for a fraction of the cost.

How to make a still air box: Keep it simple all it is is a see through tub with 2 holes that will fit your arms. The holes should be the same distance apart as your arms are and towards the bottom of the tub this will allow for more comfort. Try find a tub that is around 70litres, any bigger and you may not be able to reach everywhere inside. You can have the lid on top or bottom (on top if it is easy to see through) or if you have a nice clean flat counter to work on you can leave out the lid totally (you may have to put prestick around the bottom of the tub to stop it sliding around the table while working. There are a few ways to make the holes , if you have a drill and a holesaw set you can use that, if not you can find a suitable sized tin can and heat up the edge on the stove. Pick up the back of the can with oven mits and hold it in place over the side of the tub where you want the hole and press down to melt the plastic. Once the holes are made get fine sandpaper and sand down the edges so they are smooth and wont irritate your arms while working.

How to use a still air box: 
Clean all surfaces inside the box with a jik and water solution (it is easier if you  have this in a spray bottle) Get the SAB in the position you want to work with and get everything you will need inside, spray and wipe with jik solution, spray the surrounding surfaces again and let everything sit for 10 minutes. All particles inside will stick to the sides of the tub that should be slightly moist after spraying. (don’t make the top part to wet you don’t want water droplets dropping down over what you are working on.)
When you are working inside try avoid taking your hands in and out as much as possible. Whatever you are working on that you want to keep clean for example an open agar plate try not to move anything , even your hands over it.
Setup your SAB in a room with no moving air and with all doors and windows closed. BE CAREFUL IF YOU ARE USING ALCOHOL AND FLAME FLAME STERILISING SCALPELS AND NEEDLES INSIDE THE SAB.

What procedures can you do in a still air box :
Pouring and sealing agar plates.
Cloning mushroom tissue to agar plates.
Isolating and transferring mycelium from one plate to another
Inoculating grain spawn with Liquid Culture or Agar plates.
Pretty much anything you could do in front of a laminar flow hood.

Pros and cons of a still air box: 
Cheap and easy to build
Lets you work with cultures 
Saves you money 
Greatly raises you success rate

Working inside a SAB is restrictive and time consuming compared to a LFH
Although your success rate is greatly increased it is not near 100% as when using a LFH, and you will still get a certain percentage contamination rate.
You can only fit a certain amount of things inside at once so you are restricted with how much you can inoculate at once.