If the two 90's are back to back or close to it they could raise the pressure some. When you put the filter back together you made sure eveything lined up correctly didn't you? 16 psi should be ok to ruun with. I'm still puzzled as to why it didn't go back to original when you changed the DE.
After looking at the plumbing again. Did you change anything on the pump suction? there is what looks like new piping there. Just a thought but if the suction is less restricted than it was, the pressure could be up just because of that.
After looking at the plumbing again. Did you change anything on the pump suction? there is what looks like new piping there. Just a thought but if the suction is less restricted than it was, the pressure could be up just because of that.