Somebody try this...

[Brine]

http://www.aquatic-eden.com/2007/10/creating-waterfall-illusion-underwater.html

[beowulf]

Going to email this to Karen randall as she also wanted to know how it was done!!

[apuppet]

that water fall picture was presented when she in ottawa, and she said something about the waterfall , and something about not feasible, or white gravel,  or such. 

i didnt think i was paying attention. but im pretty sure that very picture was on the slideshow.  i could be dreaming.

[KLKelly]

Didn't someone say filter floss or nylon?  But that it would get discoloured really fast?

[charlie]

that water fall picture was presented when she in ottawa, and she said something about the waterfall , and something about not feasible, or white gravel,  or such. 

i didnt think i was paying attention. but im pretty sure that very picture was on the slideshow.  i could be dreaming.

You are correct apuppet, it was in the presentation & she did indicate not it was not feasible for a everyday tank  , good catch between winks 
Regards

[beowulf]

I emailed it to her and she thought it might have been sand and is happy to know how it was done.

[Nerine]

I love the look of that tank
now if there were a way to contain the sand haha