I haven't posted on here since the Tampa seminar due to a lot of distractions but ive finally got my business up and running and this roof cleaning is the easiest thing in the world to sell...Now, I currently use a 12V boat wash down pump for my roof cleaning. I've posted a link to it before. I believe it's 3gpm and 45 psi. When cleaning, if I turn off the ball valve, the pump shuts off due to pressure building up (I love this feature because it saves the pump).. However, when spraying, the pump does jolts of pressure. It's not contant (this annoys me like crazy).. It puts a spray then builds up pressure to do it again. Could this be because my hose is too long, low battery, something else?? Here's a gas powered pump that I'm looking into. It's made for caustic chemicals, can run dry, and is low pressure. http://www.rittenhouse.ca/asp/Product.asp?PG=41It's the same price as Pauls dual 12v pump and 1/2 price of the "roofster." Or spend $ buying the recommended delevn n fatboy annually etc.. I want to have something that will last but can clean from the ground. The pump I'm using now wouldn't reach the gutter from the ground. I didn't buy it for roof cleaning, I just had it laying around. Its time to buy a quality pump! Gary