New to the forum and in need of advice. I'm replacing a Pentair FNSP-48 DE filter with a Pentair TR100HD sand filer. The inlet and out on the filters are reversed. The multi port valve has the same mounting specs and fits perfect. I am reusing the valve. Would it be better to run in the backwash position and backwash in the run position? Or make the valve outlet the new inlet and vise versa since I have to cut and reposition due to the size difference?