The Nature2 Vessels make switching your cartridges a simple and easy task that anyone can perform. Simply plug your intake and out-take lines to and from the pool to ensure you don’t lose any water when opening the lid. Twist the lid off the Nature2 Vessel, remove the old cartridge, and replace the new cartridge by matching the footing prongs located on the bottom of the vessel to the pre-fabricated holes in the cartridge. The cartridge will sit upright and in the centre of the vessel on its own. Make sure your gasket is in place around the interior of the lid, twist the lid back on, open your intake and out-take and you’re all set!