When you get a air lock - stick your finger down the hoselock connector to release the pressure. Took me a while to work this out

Get some more barrels.... you need more than 6 - I have 13, but could do with a couple more
60 meters of 6mm microbore comes in VERY handy. ( means your not moving your trolley about after every window) - with 60 metres you can do a whole house with moving the trolley once !!!
Get yourself a flow valve from Gardiners poles... A MUST !!!!!!
Takes a few weeks to get used to the trolley and WFP, but the Pure Freedom is a great pieice of kit.