I would put in rock.
We have rocks in our wide waterfall.
Just have a plan about cleaning.
Watercress grows in our waterfall and is very easy to rip out. Lots of debris
caught in the roots
comes with it. Some rocks too - those are replaced.


k30a
and the watergardening labradors
http://www.geocities.com/watergarden...dors/home.html