On 04/08/2019 20:04, Tim+ wrote:
Why not syphons? I mean, pumps use power, quite a lot of it and are
relatively expensive. For a syphon, you just need a suitably sized bit of
pipe.

You also need an arrangement to start the siphon, which for
the scales under discussion mean a valve or tap at both ends
of the pipe, and a removable cover at the top of the siphon
through which the whole caboodle is filled with water.