Vesta Wash is a member of the Pennsylvania Apartment Association and we cleaned two tennis courts for for one of our clients in Marlton NJ.  We used Terra Wash from SoftWashSystems.com and applied using our battery powered SoftWash Systems Equipment.  We let the cleaning solution dwell and rinsed without using a pressure washer.  The key is to find the proper strength of the solution and to rinse with a large volume of water.  On this same job we cleaned the 2nd and 3rd floors of breezeways  concrete floors ans stairs to remove dirt and stains from garbage bags left outside of residents doors.  We used TerraWash on the whole job which is a biodegradeable cleaner from SoftWash Systems.  Vesta Wash is a 5 Star applicator with SoftWash Systems and operate in the area surrounding Philadelphia.