You are getting dirt and debris, it's just not visible to the naked eye. That's why the filter pressure climbs. Wait'll you put some DE in there. You'll probably see 4 psi rise in the first hour!Ok since I cleaned and topped it off and added a functional gauge the pump averages 8psi and daily builds to 12ish so I have been back washing daily as well
Edit: I assume the cloudy particles is the reason for the increased pressure. Since I am not getting dirt or debris when I backwash on both backwashes