Water caustics?

I was looking at the youtube video here and apparently from blender 3.1 there is water caustics… https://www.youtube.com/watch?v=UbWWhPmqV5E

But when I apply the settings he speaks about in my scene (attached) there is no caustics in 3.2?
MakeAPool_2ndHeightAttempt.blend (903.5 KB)

You need the beta version, it is not in the official release yet.

You need proper water surface shader- not sure if this is required but Glass BSDF works fine.

Oh boy, that worked, but holy heck, takes forever to even render a single cycles sample, let alone ten!