A filtration system for a pull-down or pull-out faucet includes a multi-channel hose configured to fluidly couple to a spray head, a water filter configured to provide filtered water, and a diverter-equipped T-connector. The T-connector has a first branch configured to receive unfiltered water from a valve cartridge of the faucet, a second branch configured to receive filtered water from the water filter, and a third branch configured to deliver filtered and unfiltered water from the first and second branches to different channels of the multi-channel hose. The spray head also includes an activation switch configured to allow selective output of filtered and unfiltered water from the spray head.