On my Pentair IC 40, I have a waffle like insert that came with the cell. Very dumb question but which end to I insert it in? I'm guessing the Inflow side to prevent large debris from entering the cell but since the cell is after the filter I think very little chance of this happening. Or maybe to minimize turbulence? On Youtube videos for cleaning the cell I never see this part and I'm really sure why? Is it necessary and what purpose does it serve?