ron p
there are more ways and chems to wash fleets as stars in the sky.
Yes, you can wash fleets.
Use the search on this site and do some homework about fleetwashing.
Then come back with some questions.
You can wash fleets with a bucket and brush/mit and just use your washer to rinse.
You can downstream your soap on and brush/mit to clean and PW to rinse.
You can add a rinse aid or wax to your tank water for spot free rinse.
There are 100's of soaps.
You could get a water softner system or de-ionized water system for your tank and do car lots.
Research the market in your area and find a ninch [spot] for your service.
Get a biz. plan. Read Read Read and learn.
Lot's of good people here that will help. Dont just look under fleetwashing.
You should start slow and learn how to wash, then pick up speed, then bid a small fleet,then move up.
Small steps,set goals,and progress.