A slurry monitoring system is provided. A filter encompasses a filter chamber containing a purge piston. During a monitor operation, the purge piston is retracted, and slurry enters the filter chamber through the filter, then passes into an outlet pipe, where a characteristic of the slurry is monitored by a monitoring device. During a purge operation, a flush valve is opened to allow water to pass into the filter chamber through an inlet pipe. The purge piston is extended to force filtered slurry from the filter chamber. The water dilutes filtered slurry remaining in the filter chamber. The flush valve is then closed and the purge piston retracted. This forces diluted slurry to pass out of the filter. This purges the filter. Diluted slurry also passes into the outlet pipe, which purges the outlet pipe and monitoring device.