To with no trouble sparkling a deck, a tension washer with a PSI vary of 2500 to 3000 is ideal
https://wiki-byte.win/index.php/Choosing_the_Right_PSI:_How_Much_Pressure_Washer_Power_Do_You_Need_to_Effectively_Clean_Your_Deck%3F
To comfortably clean a deck, a force washing machine with a PSI stove of 2500 to 3000 is perfect. This power point effectually removes dust, dirt, and mold with out negative the wood