"B." wrote:

I currently am using a pressurized tank to inject co2 into my tank. I was
wondering what was the safest or most effective pounds of pressure that
should be released. I was running it at 20 but i have cut it down to 15 and
seem to be using less co2. But i also heard that at these low levels my
dual guage will break quickly. I s this true?

No. You should probably set a range between 10 and 20 psi, then use your needle
valve to adjust the number of bubbles per minute you want. Then, check
continuously over a period of days to see if that setting stays stable. This is
the most important issue-stable output you can depend on.

Higher pressu often more stable, but harder to make fine adjustments at the
needle valve (like going from 30 to 35 bubbles per minute)

Lower pressu often less stable, but fine adjustments at the needle valve may
be easier.

All of the depends on your exact equipment. Try it and see.