wrote in message
.. .

You really should get a regulator (they are quite inexpensive).
That way you can have infinite control over your CO2 output.
I use a 75 lb bottle connected to a 4 port (each port has a valve)
header at the regulator. From there I feed a 1/4" line which branches
off into seperate valves at each tank. My bubble rate for most tanks
(70 gal. average) is 1/sec. Plants and algae are doing great

Well, I don't really need very fine control. I'm putting the CO2 into an
external Reactor 1000 by Aqua Medic (see
http://www.aquaristikshop.com/e_arti...actor_1000.htm).
That one is so efficient at dissolving CO2 that it doesn't matter whether
you run 5 or 50 bubbles per second. A pH meter connected to a controller
and solenoid takes care of switching the CO2 off when the pH drops low
enough, so I don't have to worry about poisoning my fish.

But, you are right -- it's much nicer to have a regulator that allows
adjustment
of the working pressure and, if you don't have the CO2 supply on a pH meter
and controller, it's pretty much essential in order to get consistent and low
bubble rates.

Cheers,

Michi.

--
Michi Henning Ph: +61 4 1118-2700
ZeroC, Inc. http://www.zeroc.com