I started out 6 months ago by using a wcw backpack, 30 ft pole and 25L containers along with the RO and storage.
6 months from starting I've outgrown the backpack and have got a van and my system is on its way.
The backpack was not only a great tool for me just starting out, but extremely cost effective being new and not having much to spend when starting out.
If it wasn't for the backpack, I wouldn't be where I am today (I may not have even been a window cleaner).
My backpack will go part time once my van system is installed. It has a place in my business and I would always haveit to hand