Sounds good. Maybe decrease displacement around the pool and make it muddy.
If you use some very warped colored fractals on a surface shader, and add a reflective (maybe increase the 1.33 to 1.
shader after the fractals, surface shader masked by a warped ridgy fractal, and add that after the water shader, you may get some nice oily effects.
If I type an 8, you get a smiley, huh...