I’m a fan of backwashing more frequently. Every two weeks. You don’t have to backwash long, you just have to backwash until the water runs clean. As the pressure increases, it puts a little more strain on the system so why not nip it in the bud? If your pressure is running at 20% higher for a week, that’s added pressure on the system you don’t need. Backwashing seems to alleviate a lot of problems.