Pressure washers are a very important component of using a soap cannon, and while it is not always essential, it is the best way to get excellent power when using the soap cannon.
It is important that you use a pressure washer that has a PSI that is suitable for use with your soap cannon. Once you have ensured this, you can then connect your soap cannon to your pressure washer.
You can do this using the hose that is connected to the pressure washer, and if need be you can use an extension hose to extend the distance between the soap cannon and the pressure washer.
But connecting your pressure washer to your soap cannon is very simple, all you have to do is connect the hose and you are good to go.