"The best way to deliver CO2

"Between the regulator, which is attached to a bottle of carbon dioxide, and
the
reactor or membrane diffuser, manufacturers of aquarium equipment generally
supply us with silicone tubing. However, this kind of tubing is highly
permeable
to CO2. This becomes increasingly worrying as the tubing gets longer.

"What happens?

"Part of the CO2 which is passing through the silicone tube crosses the wall
of
the tubing, and enters the air. Tests have recently shown that this can
cause the
loss of up to 30% of the precious gas. I and a partner in the
pharmaceuticals
industry have run tests on no fewer than 10 kinds of tubing. As you might
have
guessed, silicone tubing turned out to be the most permeable of all, that
is, the
tubing which allowed the most gas to escape.

"A solution to the problem?

"Yes, there is a solution! The American company Cole-Parmer manufactures
and
distributes tubing made of TYGON®, which does not allow CO2 to get through.
It is affordable, unlike the silicone tubing typically found in pet stores.
Its
reference number is R-3603. Being flexible, it is well-adapted to our
installations. TYGON tubing exists in many interior and exterior diameters.
It is
not necessary to buy the thickest tubing available, but a thickness of 0.8
mm is a
reasonable minimum. Obviously, the thicker the tubing, the more resistant
it will
be as time passes.

"I would encourage all users of CO2 systems to change their silicone tubing
for
TYGON® tubing from Cole-Parmer. This will result in substantial savings of
this precious gas, as well as a better functioning system. It's nonsense to
mix in
air with the CO2 and water in the reactor.

"I have now observed much better dissolution of CO2 in my Dupla S reactor.
Air had regularly been mixing in with the CO2, causing some useless free
space
to be left over in the upper part of the reactor. Since I have been using
the
TYGON tubing, the CO2 is practically all dissolved. I have observed that
the
efficiency of the reactor, which is already quite impressive, is now even
greater."

================================

Please note: I'm playing journalist and translator here. I don't know
anything
about tubing (silicone or Tygon or otherwise), nor do I know anything about
Chicheret. I've tried to keep my translation fairly close to the original,
even when the French sounded odd (e.g. the reference to "precious" CO2).

David (B.)
Paris