I have a home-made 500 gal hydro seeder. It has a 3" trash pump, with a 5hp Briggs motor, for the seeder and provides aggitation by overflow pressure from the pump. I built this unit myself from a picture of a smaller unit. I have used it on about 8 jobs over 4 years. The unit is on heavy duty skids and has 3 sections of 1 1/4 inch hose, each with 50 feet. It works very well if you have the patience to practice with it and become proficient. If you have some small lawns to establish, this would cost about 50% of what a sod job would be. If interested you can contact me for px. Delivery is a possibility. Asking $3500.00.