10 days to 2 weeks in advance - physically put your hands on every part of your drain & fill system that you plan to use for draining your mattress. This way you know you have what you need. If your mattress has fiber in it, consider buying a pump or renting one.
A wet dry vacuum cleaner works great for that last bit of water of you have a hose end adapter that is connected to a male water hose connector. See below.
1 week in advance - Order Waterbed Conditioner. You will need new conditioner after moving.
The day before - Stage your drain and fill kit and or electric pump and or vacuum setup.
Check Off List of What You Need
A clean hose is used for draining your mattress. Old hoses or garden hoses can introduce bacteria and other things into the mattress. A 25 foot hose often will not reach far enough. You may wish to pre-measure hose length.
Faucet Adapter allows connecting Venturi Pump to sink
The Venturi Pump connects to the faucet. When the rotating valve on the bottom is in the down position it removes water from the bed. In the up position it puts water into the bed.
The Perfect Union allows connecting a hose to the mattress
O-Rings keep seals tight, you cannot drain a bed if everything is not airtight.
Waterbed Conditioner should be poured into mattress if it is to be stored for a period of time.
If moving right away you will need to have this so you can set your bed up right away.
If you don't have everything you see above, you are not ready to drain your mattress.
Optional - A Water Pump can be rented or purchased in advance. If you have a fiber filled bed you really need this.
Optional - Using a Wet-Dry Vac™ is a great way to get out the last vestiges of water and allows you to vacuum pack your mattress.
vacuum packing is the best way of keeping the fiber layers from shifting.
Most companies that sell wet dry vacuums also sell vacuum hose adapters that allow you to step down their hose to a water hose size.
This common brass replacement fitting can be connected to the adapter.
A Radiator Clamp is used to seal the vacuum hose adapter to the brass hose fitting.
Here we see the adapter set up allowing you to vacuum out the last vestiges of water and also vacuum pack your mattress for moving or shipping.