You need to find a plumbing center
PVC pipework works fine for this.
Make sure though that you ask for the outside diameter as pipework is usually measured from internal.
The pipe will be fine as pretty much nothing sticks to it due to the coating.
Just dont spray the pipework with anything first as it will lose the slippery surface.
Also, make sure the pipework sticks up atleast 3-4 inches out of the water.
This seems wasteful, but it gives you a good grip on it as you will need to twist it lose.
Also, when you cut the pipe with a saw it leaves a jagged fluffy edge which you will need to trim with a knife to make it smooth again.
I have done this a few times for display bases that i want a playable model to sit in.
Its quite easy to do, just takes some time.
Hope this helps