Thanks Ludvik,
With the pool, I'm finding ripples, waves etc.. distract the eye from seeing the bottom of the pool, with a flat surface I get the depth of the pool.
I don't know whats better ? But I'll do another one to see the difference.
Grass, I have two different patches, one longer and the short one, I'll up the frequency of the longer one so its visible in these close up shots.
I just realised this is an older render, I'd recently built timber edging around the decking, will update it.