I use this manifold on my 75gal.this is probably one of the best examples of how a hillstream should look.
The water passes under the scape since its elevated.
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Although a nice setup, for my own personal opinion, this is more of a river setup as the flow makes the bottom slower moving than the upper column.
Don't get me wrong I really like it. And use it to good effect.
But to be a “hillstream” stream, you need serious investment into circulation pumps.
The best for hillatream-like flow, I have personally found circular, unidirectional flow to work best. Horizontal, back to front circular. Not vertical, over under.