It is very important when doing any big modifications to your pond or filter system that you arrange some temporary filter system preferably using your old filter media.
In this case Keith had decided that he would empty out his old filter and raise it up to ground level. He would then use a submersible pump to pump into the filter and return the water by gravity to the pond.
Unfortunately when he installed a larger filter some years ago it was a very tight fit into the original space. Over the years the tank has deformed slightly with the weight of water and resisted the efforts of several men to remove it in one piece.

It was then decided to use the Nexus as the temporary filter whilst the old vortex chamber was being removed and the new base was laid.

The old filter was using 150 litres of Kalnes K1 so this was put into the Nexus filter.