The present invention features a fertilizing device for installing in a water system comprising a top cover removably and sealably attached to a base； an intake pipe disposed on a first side and an outlet pipe disposed on a second side of the base, the intake pipe and outlet pipe are both fluidly connected to the inner cavity of the top cover； an open container with apertures disposed in the first and second container side walls for holding a fertilizer bar； wherein the intake pipe is connected to a first portion of a pipe of the water system, the outlet pipe is connected to a second portion of the pipe of the water system； wherein water from the water system can enter the intake pipe, mix with the fertilizer bar, and exit via the outlet pipe.
