I have an 1800psi Husky electric power washer. I plan on washing my house (vinyl siding w/aluminum trim) and my deck made out of treated lumber. All of which is 10yrs. old. I was thinking about TSP or deck cleaner (probably just premixed TSP). I don't care about the wear of the chemical on the power washer and don't want to have to purchase multiple cleaners per surface being cleaned. My question is: What chemical cleaner can I add to the detergent tank on the power washer that won't leave stains on opposing material and is also biodegradable?