i don't know if this helps, but here are pics of how i made a removable water feature for my paludarium. i decided against using it, but it works well.

because this was planned to be removable, i had to lay the plastic wrap don to prevent the foam from sticking to hat i had already foamed

i then had a frame that held the pump (you'll see in a later pic), the tubing and the reservoir. this was going to have an ultrasonic fogger in it, hence the reservoir.


foamed the **** out of it. this was my design, you can use the same method covered by anything you desire.

i then ended up with this monstrosity that i carved and covered




i hope that helps