The dry setup is handy if you want to place the pump outside the pond, for example in a technical pit. Keep the filter lid off, or leave the pump in it, and fit a hose connector with an o-ring on the outlet, then repeat this for the inlet. Make sure the pump always stays below the water level, since it has no dry-run protection and could run dry. You can also place the pump inside the debris basket and close it off for a stable dry setup, for example for a skimmer connection or a drain hole.