Hi, I run a 3600psi machine, and for all my jobs use a turbo nozzle which i find great. Ive also got a northstar surface cleaner (blue1) but i never use it because it just dosent clean properly even keeping it on the same spot on full power and it certainly wont fetch moss or weeds out? you always see these vans or websites with pics of a surface cleaner with a before/after making it look perfect! can any1 explain why?