I now have a waterbed in my crawlspace!
Ok - just the bag, not the whole frame. I didn't see any good reason to shove the whole frame down there.
I got a garden hose "T" which includes 4 shut-offs built in, which will make it much easier to hook everything up, and even drain the mattress as well.
I do NOT have a bit of hose that sticks down into the mattress, but I will burp out any air from the mattress before finalizing the setup.
Preliminarily, it's looking pretty good.
Here's a garden hose manifold with integrated shut-offs. The blue connection is what connects to the waterbed.
Here's the custom end connection I used to make a "female to female" hose to connect the mattress to the pump.
Next thing is that I am going to need a pretty decent filter. I do NOT want lint and ickyness going into the waterbed. Pretty easy to wash out a garbage can....not so easy with a mattress!