I want to reiterate the only correct way to do a canard fuel
system is follow the Ruttan plans. To do other wise is risking
your life. Reproduced here in gif form.

If you have a EFI high pressure fuel system with return
flow use a high quality dual level selector valve and return the flow
to the tank you are sucking fuel from. Not the sumps tanks. (there
are two in the stock canard system.) There are a lot of factors and
scenarios to be taken into consideration when designing a fuel system.
Some of these factors are:

Vent configuration. Air pressure in the tanks under all conditions.
Heat of the return fuel. Position of the HP fuel pumps. Height of the fuel tanks
affecting the gravity flow. Size of the lines. Quality of the fuel
selector valve if used. Shape and location of the sump tank.  Etc., Etc.

The only difference in my 3D below is the depth of the sump tanks
which should lengthen the time the engine will still run during
slips or uncoordinated turns. In the stock system they are integrated
into the main left and right tanks. Make the connecting lines between
tank and sump as large as possible. Keep the high pressure
pumps as low as possible and as close to the selector valve
as possible. Don't use a both selector valve. It has no place
here. Tall and skinny sump tanks are essential. Don't make
them wide.

The vent lines to the main tanks are facing forward to
enhance the flow from the main tanks to the sump tanks.
The sump tank vent lines are not facing forward to insure
the air pressure in the sump tanks is not the same as the air pressure
in the main tanks. At real high speeds it is possible that
the air pressure in the main tanks could force fuel out of the
sump tank vent lines if they are less than about 28 inch high.
If that happens face sump tank the vent tank lines forward as well
to equalize the air pressure. Do not route the vent lines
any other why as a siphon situation could be set up.

Don't fool around with it unless you are a highly qualified mechanical
or aerospace engineer.

There are some unmoderated list out there in Internet land where
every poorly thought out half baked scheme is given equal weight.

Paul Lamar