Garden Hose (Mount Florida G42)

Need a Garden Hose to attach to a Power Washer unit which I didn't know needed a Garden Hose to work. I bought it to clean up the gunge-moss stuff causing neighbours to slide and fall out front of our closes, didn't realise until I got it home that it didn't have a water tank and needed a Garden Hose attached to it to supply the water it needs to work. A couple of neighbours next close try to avoid going out because the gunge-moss is so slidey. The properties in these two closes have different Housing Associations as landlords so getting them to do anything is a nightmare so I'm trying to help out.