Amount of water needed to WFP 40 windows

I know this will vary, but on average how many gallons of water is needed to clean 40 average size casement windows on a residential home? Assume that the windows haven’t been cleaned in several years.

I am considering purchasing the Reach Higher Ground / RHG Backpack Delivery System and needed an answer as I was wondering how many times I would need to stop to refill it to complete one residence first and second floor windows.

If it took you 3min per window and your poll uses .5 gal per min that would be a gallon and a half per window with no waste 60 gallons to clean 40 windows.

Doesn’t it seem like a lot of time per window? I recacll a video with a set of french doors with 9 panes each being cleaned including the doors and frames in less than 3 minutes. One average size casement window in under a minute easy I say. But then again I am new to this WFP as well but thats how long it takes me anad it seems to work out. [B]You’re going to need more than 20 gallons though /B. It will depend on how much time you spend on the frames and how proficient you are.