I'm with you man. I started with a 12 volt pump for chemical delivery and now have a diaphragm system. The pressurewasher is strictly for rinsing and surface cleaning. I love the control we have with a separate chemical delivery system. Downstreaming didn't work well for me and I'm glad it didn't. If one particular house is much dirtier than normal, I can just add a gallon of bleach and not have to reapply a bunch of times. Downstreaming, your just stuck spraying the damn house 6 times, lol.