Right, since posting last time i've maintained a chlorine level of about 10ppm using stabilized chlorine granules. The pool wasn't getting any clearer or milkyer so I decided to switch the pump off to see if it settled.

After vacuuming to waste last night (in the dark by the time i got home!) I re-shocked with 10 litres of liquid chlorine. I also added a little acid as the ph was at 7.6.

This morning the pool looks a little clearer (i can see the bottom step in the shallow end) however it is still definitely green, not milky.

Am i heading in the right direction?