Fish highway in garden
I was working on an aquatic system for fish, formed of a series of aquariums. there would be a waterfall going form one aquarium to the next and a pump returning the water. BUT. what is important is that the waterfall allow the fish to jump back up. i am not sure if there should be a fish ladder or simply a low waterfall. Possibly a fish elevator, which needs to have few moving parts, maybe in the form of a water wheel or a chain of buckets. another thought was an Archimedes screw or even a tube which is filled with water by pump to keep it form emptying. need some way to convince fish to go in… another issue is that any significant height differential encourages the water to empty out rather fast from any permanent opening large enough for fish. closing openings, can pinch fish.
in any case, project stalled due to my dislike of cutting holes in glass aquariums.
This list is not complete...