Single valve ready to use hose end sprayer

Disclosed herein are various embodiments related to a chemical sprayer that includes a sprayer head assembly and a container. The container defines a cavity for storing a chemical to be sprayed. The sprayer head assembly includes a chemical passage, a carrier fluid passage, a vent passage, a valve chamber and a valve. The chemical passage is communication with the cavity. The carrier fluid passage is in communication with a carrier fluid source. Both the carrier fluid and chemical passages are in communication with the valve chamber. The valve is moveably positioned within the valve chamber and defines at least partially a first passage and a second passage. The first passage is configured so as to be in communication with the chemical passage when the valve is in an open position. The second passage is configured so as to be in communication with the carrier fluid passage when the valve is in the open position. In one embodiment, the assembly also includes a sealing member that may be biased in one direction and actuated to open and close the vent passage.