sorry i should have mentioned in my first post.
atm we simple plug into the customers outside hose, this goes into a DI cannister and then straight into our pole. All the pressure is from the customers water supply. no tank, no R/O.
i know we should use a pro window cleaner, however the situation is that no one wants the work. For instance i've just booked a job for this wednesday where we are cleaning the whole house as she's moving out and she wants the externals done too. To get someone to agree to go to this town, with 2 days notice, and at a price the customer would pay, it's never going to happen and i've tried. i offer this service as a small additional extra, let them know exactly what to expect and that they must have an outside tap for us to use.
we do this service so infrequent and when we do it's just one house, so little water is needed. Having an R/O system that fills up a small tank while we are cleaning the other parts of the house is fine, and then i guess draw from this with our pole, but i'd need a pump. I would need recommendations as to what /o, tank, pump etc.
the pump would only be used 20 or so minutes and then not again for another day or so.