I have a 400 gallon hydroseeder that I would like to make larger, say to 800-1000 gallons. It has a mechanical agitator (paddle) in the belly of the tank, so that is a consideration because I don't want to damage how it functions. Has anybody done this before? What should I be careful of? It is just so expensive to buy a larger unit, and it would cost a lot less to cut the tank and weld on another section of tank, as long as I do it right! Anybody in Eastern MA know of some good welding people who could do this?