On Sun, 1 Feb 2004 23:21:04 -0500, "Paulo" wrote:

Id like to try this one. can you explain how and where i should conect the
tubing? How can you regulate the CO2 that gointo the tank?
Thanks

If you choose to use a pop bottle (I did, simply because it was
convenient), find an airline hose connector/adapter. I found a joiner
laying around (so you can join 2 pieces of airline into one large one
- no valves or T-joints or anything) and use that. I drilled a hole in
the lid of the pop bottle that just fit the joiner (but the "lip" at
the center of the joiner wouldn't pass through) and fastened it with
epoxy glue. It's airtight, strong as hell, and simple to connect.

As for regulating - a lot of websites give advanced systems using
pressure regulators et al.. Airline hosing and the glue job I did on
the pop bottle probably wouldn't take a whole lot of pressure, so I
just let it bubble freely into the tank - any nondiffused bubbles just
overflow the diffuser and go to the surface.

Total cost (assuming I didn't have my materials laying around) was 20
cents for the pop bottle deposit, a buck for airline hosing, and 50
cents for the joiner.
The diffuser is another story and I'm still thinking of ways to make a
cheap, simple one. The powerhead-driven one just doesn't appeal to me.