Delta faucets do not require routine scheduled maintenance. Only if the faucet is leaking or fails to supply water is any attention needed. This is true even for areas where the water supply has a high mineral content.
As of 2015, the Delta website has four how-to videos showing how to handle leaks and lack of water delivery, but none that mention any routine service. One occasional problem is that the water stream delivery can become uneven. This is usually caused by sediment particles clogging the aerator screen. The problem can be fixed with a pair of pliers and a soft cloth to protect the faucet's finish.