Lynn, thank you for the advice and also for the link. That really helps and I will see if I can do justice to the info. I've finally got something workable...now the question is: can I make it look good. I think the silicone will help to make it more realistic. If not, I will redo the waterfall and use the silicone for the entire thing. However it turns out, good or bad, I'll post the results and maybe someone will get something out of it. I'm having fun doing the scenery but I didn't realize how time consuming it is. Live and learn.