All you need to perform these kind of photos is a ND filter. The ND filter lets you keep longer times without overexposing the picture. This picture is 20 seconds with ND400 which darkens the photo 10 times. The water turn milky and the reflec burn into the water. The longer time you can set the more the water and the clouds get blurred and the more the shadows burn into the water. With 20 sec you can hardly see the reflex from the sticks in the water. I will publish a DIY help for how to create your own ND filter. Very easy and good results.