I'm glad I was able to help, and offer perhaps a "different" approach(even though this has been used by the zoo exhibit industry for decades) than what is commonly seen on these online fora.
Looks good, did you happen to waterproof it? The reason why I ask, is that cement, and all of its different aggregates are very porous, and will suck up water just like a sponge. When working with cement in waterfall applications, it is important to apply a waterproofing membrane to the areas that will be physically in contact with the water. Otherwise, the structure will ultimately turn into a big sponge.
There are two products which I have used successfully in the past. One is a granular compound named Xypex, which is mixed directly into the aggregate as you are mixing it with water, prior to application. As the cement cures, this compound closes the cells in between the cement granules, thus waterproofing it. The other product, which I used on the waterfall I posted photos of a couple of weeks ago, is called DryLoc, and is a latex-based waterproofing membrane which is painted onto the cement. Because this has a glossy and "paint-look" to it, I place apply this membrane in between the structural and textural layers of the waterfall, in the areas that will be exposed to/in contact with water. While the top layer/textural layer will suck up some water, it will not penetrate into the main body of the structure.
Good luck, looking good, be sure to post some photos of the finished project! Cheers, and happy creating!
Bob
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