Hi Ed

Actually its Coriolis Force, named after its discoverer
Gustave-Gaspard Coriolis in 1835.

It has been proven to affect all bodies of liquid regardless of size!

Drain your sink of less than 1/2 gallon or flush your toilet of 1.6
gallons, these are much smaller than the majority of aquaria.

Ascher H. Shaprio proved the effect again in 1962 at MIT and Lloyd
Terfethen did the same at the U of Sydney in 1965.

In an aquarium, the effect may be miniscule, but it is still there
just the same. So why not keep your aquarium flowing with the natural
order of things, rather than trying to go against mother nature.

As an aside, a major contractor built a rather large fountain and did
not take into account Coriolis Force or the Curvature of the Earth.

When the fountain was filled, water did not pour over the length as
intended, but flowed only out the center. With the greater part of
the water at the apex of the counterclockwise rotation. Of course,
this was a very large fountain too.
However, the same effects would be found in even the smallest
fountain, but to such a reduced degree that it would probably not be
noticable without the most accurate test equipment.

The moon also plays a very miniscule part on our aquaria. On large
public aquaria a difference of as much as 1/2 inch can be noted
between neap tide and full tide. On a large body of water, the water
level in a large aquarium can be determined with fair accuracy using
either the Rule of Twelves or the Rule of Sevens.

TTUL
Gary