A gravity-fed carbon block water filter in one embodiment includes a filter block comprising multiple sub-blocks each comprising filter media walls surrounding and defining a cavity for receiving fluid. Each of the sub-blocks is connected to at least one other of the sub-blocks by filter media of which the filter block is made. In one approach, the filter media includes about 20-90 wt % activated carbon, and about 5-50 wt % binder. In another approach, a lead concentration in a final liter of effluent water filtered by the filter is less than about 10 μg/liter after about 151 liters (40 gallons) of source water filtration, the source water having a pH of 8.5 and containing 135-165 ppb total lead with 30-60 ppb being colloidal lead greater than 0.1 μm in diameter. A gravity-fed water filter in other embodiments has no specified shape but achieves a FRAP factor of about 350 or less.