How big is it?
My opinion on small skimmers on small tanks:
Small skimmers do not skim very well. Usually you will be better off on small tanks just doing water changes, and/or running media to export nutrients.
Put the mp40 on the bottom pointed up. I swear the flow in the tank is at least twice as good as when it was on the side panel. The tank is 32” wide, 24” front to back, and 20” deep.
I wouldn’t even worry about it. You’re going to do more harm than good trying to chase an “ideal” number.
Pay more attention to your alk and keeping it stable.