Sorry I didn't get back sooner . I had 2 units - a 3,000 psi Xcel with a 500 gallon tank mounted in an 18' Mercedes straight truck I bought from Ryder and a 2,000 psi Hotsy with a 100 gallon tank in an F-250 pickup . The Hotsy was adequate for most jobs . I would rent the rigs to the mud racers when they came around with the monster trucks every year as well as mud boggers at county fairs . There's a wide variety of chemicals available . Grainger sells both the washers and chemicals
Janitorial & Painting > Chemicals > Automotive Cleaners and Protectants > Vehicle Wash,5 Gal : Grainger Industrial Supply . I liked buying from Grainger because the prices are good and they give full info including the MSDS . You want biodegradable products if possible . It's most economical to brush the chemicals on rather than use chemical injection on the washer . It wouldn't hurt to keep a spare hose . Burst hoses can be repaired at shops selling and servicing hydraulic hoses . I'd watch eBay and local auctions for a good buy . When there is a chance of freezing weather run windshield washer fluid through the machine and hoses .