An apparatus for growing ingots by the Czochralski method includes a growth chamber defining an enclosure configured to circulate a purge gas about the growing ingot and a crucible provided in the growth chamber configured to hold the molten silicon. A weir is supported in the crucible and is configured to separate the molten silicon into an inner growth region surrounding the melt/crystal interface from an outer region configured to receive the crystalline feedstock. The weir comprises at least one sidewall extending vertically and a cap extending substantially perpendicularly to the sidewall.