I've completely redone that pool. When I did the one in the screenshot I hadn't read the tutorial yet so I wasn't aware you could make the water semi-transparent.
The pool in the shot is only 6" deep (15.24 cm). The new one is 6' deep (182.88 cm) with sloping floors and I'm adding lights now.
It also has an underground pump room with a window into the pool, underwater.

I'll post some shots in a couple of days.