Which adapter for aquaroll? (Powered)

You need one of these:

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which will plug into the Whale inlet socket on the side of your van.  A-S provided one with my coach built van in 2019.  It gets its 12V from the two brass contacts you will see on the Whale inlet socket.  The Autofill has to be turned on at the EC700 CP for it to work and when the fresh water tank is full the 12V supply to the inlet socket and therefore the pump will cut off.  You should shop around for the best price.  I believe there are different models with different flow rates but they will all work.

The  hose you have also plugs into the Whale inlet socket and is as you say for when you are on a super pitch but also if you wish to fill your fresh water tank at a motorhome service point.  As with the Whale watermaster pump, the Autofill needs to be turned on for it to work and when the fresh water tank is full it will cut off.  The hose can be used like a normal hose if a spigot is inserted into the Whale plug end.  This should have come with the hose.

There are quite a few owners who don't use a water roll and therefore an external water master pump.  This may be because they don't have space for the water roll or they regard it as too much like a caravan.  They may also begrudge the use of electricity to fill their tank.  These people often use a watering can or other hand held container to fill their tank.  I am not one of these people and use my water roll and pump in preference to using a hose at a motorhome service point.  I still use the hose but only on pitches that have a tap.