Phil
Sit tight Phil with this posting as its a long one.
The first picture shows the taps to be isolated - these taps are incorporated in the water return pipe (centre pipe on a 2080).
Second picture shows the taps isolated.
Third picture shows the taps disconnected.
Four picture hose pipe connected - taps still closed.
The other end of the pipe is placed into the sink unit, the taps are open and the water flow out of the tank via the filter unit. Flow is slow at the minute
Flow improves in the this picture as the filter unit is power up, so the water is pumped out.
50% of water removed - now its time to refill the tank.
Hozelock connector added to hoze pipe and this is attached to the sink mixer tap.
The other end of the pipe which was connected to the filter unit is now placed inside the tank.
dechlorinated is add whilst tank is been filled up.
The joint that was diconnected is reconnected and the taps are opened.
Pump switched on and the taps are opened / closed to prime / remove air from within the filter the system.
Tank full of water - no air locks - finished approx time 30 mins.
Hope this helps with your water changing.
Regards
paul.