Hi, I rigged up a removable fountain on my intex ultra frame pool. I haven't done any hard plumbing, but thought the kids would like a fountain. I used ABS and the blue adaptor to connect to the water return outlet. I didn't glue the blue piece to the ABS (but did do the rest of the connections), it seems to hold enough by just sticking it in. This also allows for a bit of adjustment and makes it easier to screw on. When you are done playing, just unscrew and remove.
Here is a pic