Thanks for the replies guys.

Matt---I can valve off maybe 400 of the taps at different points. When I tried flushing before I tied off the mainline loops with a tie wire to block sections of lateral, only trying to flush say 4 laterals at a time.

Brian, Thanks. Does your washer only use fluid or does it use air as well? As Doctor Tim and Dave stated I would be very concerned about splitting poly mainline and blowing fittings. If you are lifting over 800' you must be building some high pressure?

Cleaning from the top would be tough I think. By my math a 100' run of 3/16 would have about 5.5 gallons of fluid in it. Basically 1 backpack sprayer for every one of my 50 laterals (some are only 300-400 but they do reach 1000). If I had a 4 wheeler I could maybe tow a 50 gallon tank up there but I don't. In the future I will be switching to a traditional high vac system on 5/16...the 3/16 is just lots of work.

Jack