Aqua-Hot GREEN fluid-where to buy ?

I'd be leery about buying coolant by color. Most modern Hydro Hot/Aqua Hot systems (manufactured within the last 10 tears) use a propylene glycol based boiler fluid, which is normally pink. But some systems, particularly older systems, use ethylene glycol, which is conventional automotive coolant, and can be any number of colors. I would review your literature or talk to Winnebago or Aqua Hot and make sure you know the proper fluid for your system.