An aspiration-type sprayer assembly adapted for being coupled to both the end of the hose and to a chemical container has a housing including a carrier liquid inlet passage, a chemical liquid inlet passage and a discharge passage. The cylindrical rotatable valve within the housing has a carrier liquid duct and a chemical liquid duct opening into the carrier duct for interconnecting the inlet passage in a first rotative position of the valve, and the valve is capable of closing the inlet passages in a second rotative position of the valve. The rotatable nozzle versus the discharge in selective directions, and the assembly is capable of being manipulated by the provision of a handle grip. An anti-siphon assembly is provided at the coupling between the sprayer housing and the water hose end to avoid pressure and back flow from the sprayer. And chemical/water mix can be exchanged substituting the various tube retainers having different size inlet ports.