A chemical feeder for dissolving chemical tablets includes a housing and a plurality of tapered pedestals positioned in the housing for supporting the chemical tablet as the tablet is dissolved by liquid flowing through the feeder. The housing also includes a cup configured to receive a cartridge for holding the tablet; the cup includes inlet and outlet ports for the liquid. The cartridge includes a plate at its lower end; the pedestals are formed on its interior surface. Each pedestal may have a pencil-point shape. When the chemical tablet is installed in the cartridge and the cartridge is installed in the cup, the tapered pedestals support the chemical tablet and thereby expose an underside of the tablet to the liquid. The tablet is immersed in the liquid according to the height of the pedestal; the dissolution rate of the tablet thus corresponds to the height of the pedestals.