I have no idea if the silicone will hold, but time will tell. Its a learning experience.

Here is the second view, not sure if you can tell but the waterfall is nearly flat. It will be positioned in the corner and I will add some acitvated carbon (charcoal) inside a bag of pantyhose, then cover it all up with some filter floss or a foam sleeve topped with a few rocks to hold it all in place and keep the toads out of there. I decided to make my own because the price of the waterfall combined with the space it would use up was more than I wanted. I also plan to dress it up by sticking some plants in the crevases in the waterfall.
Here is the tank, I just assembled it last night so I haven't yet trimmed the excess silicone. I also haven't cleaned it yet, that is what I will do after dinner. And before anyone tells me the gravel is too small, thats the base layer, I have some larger gravel that will go on top. I'm not ready to try moss or coconut husks yet. In time I will get brave.