   Greetings, "New kid on the block..." [Have a real name?]
Glad to see someone who does not mind doing some homework.  yeah
I do have a real name....and if you say the ID real fast out
loud you'll get the real name...Just a very unique way of
spelling it...  I do this to keep a layer of privacy on the
net...  > Hi > New kid on the block... > two questions... I was
catching up on this Co2 thing and tubing.. so what's > this big
deal about co2 resistant tubing??? and why the concern???  Vinyl
tubing, as used for regular airline has plasticizers that will
interact with the CO2 with potentially undesirable consequences.
Even if those don't add stuff you don't want to the aquarium,
the erosion eventually hardens the tubing and may make it stiff
and brittle over a long period of time. [I've never seen that,
but it has been reported, I  Silicone tubing has long been used
in hospitals as it has less interactive chemistry, so is
suitable for even oxygen as well as CO2 lines. Unfortunately, it
is more rubbery and str