First of all, thanks for all who like this layout, your appreciation and your comment. I think all of you interest how the waterfall recreate under water. The idea is from a very famous scenic in China - Jiuzhaiigou valley, below are the waterfall from Jiuzhaiigou
http/images.google.com.hk/images?q=%E7%8...l&start=20&sa=N
The secret is the fusion of filter floss and ADA Rio Negro Sand, I try different white sand cover the stone, the effect is not that attractive, some of particle is too rough, some of that are too white. Finally, I choice ADA Rio Negro Sand, the particle is fine and most of the particle is Silicon. The visual result after photo is perfect. It reflect as white but still have some texture detail.
My first idea only use sand to replicate, however it is not satisfied, it just like a white banner not waterfall. I look back my reference picture, it seems lack of water motion and splash, I notice that when water pass the stone, it would form as a foggy layer. I try different material to simulate this effect, finally I choice the filter floss, because it would not contract together in water even I tear it off to a very thin layer, and the texture is very close to the effect of moving water.
According to my experience, even though you have all this, if you don’t know how to arrange the sand, stone and floss, it still does not have this result, I try many many time and finally get this result.