RE: Two tanks, run by one canister filter

[Mike Wickham <mewickham at compuserve_com>]

 >> Put them together in a "U" shape and lower the "U" into your tank so
that
 >> it gets filled with water.

While it is possible for this method to work, it works ONLY if the level of
the two tanks is exactly the same. The original poster wanted to connect a
10-gallon and a 20H-gallon. One tank is fully 4" taller than the other.
That means that 4" of water from the 20H will siphon into the 10-gallon as
the water attempts to achieve its equilibrium. In other words... flood. For
the siphon tube method to work, the 10-gallon will need to be boosted an
extra four inches.

Also, there is a real danger in using opaque PVC pipes for siphon tubes.
You can't see air bubble collecting inside at the top of the inverted U.
With the large diameter, slow flow U-tube recommended, air bubbles WILL
collect in the tube. Over time, they will form an air pocket large enough
to cause the siphon to quit. In other words... flood. How fast bubbles will
collect inside depends, but it usually happens quicker than one would
expect.

So, while such a method is doable, there are serious caveats. I cannot
understand why a person would go through so much extra expense, extra work,
and extra risk just so they could run one new filter instead of two
existing ones.

Mike Wickham