Co2 Runtime estimator

Tool

CO2 Tank Runtime Estimator

Estimate how long your CO2 cylinder will last based on your use-case. This won’t be perfect (life is messy), but it will be good enough to stop you from guessing.

Estimator

Inputs

If your tank is dying “way too fast,” it’s usually a slow leak or inconsistent hardware. See troubleshooting.

Results

Enter values and click Estimate.
This is an estimate. Your real runtime depends on leaks, regulator stability, injection schedule, and how chaotic your setup is.

How it works

Simple math

Runtime is basically: tank capacity ÷ monthly usage. We include an optional efficiency/leak factor so you can model “real life.”

When to override

  • If you know your usage rate, enter lbs/month directly.
  • If you’re guessing, the lane presets are just a starting point.
  • If your setup is new or finicky, bump the factor to 1.2–1.4 until it stabilizes.

Tips that extend runtime

Fix leaks first

A tiny leak empties tanks surprisingly fast. Soap test threaded joints and check valves.

Stability beats “more”

Especially for aquariums: stable CO2 on a schedule often uses less gas than constant tweaking.

Choose the right size

Bigger tanks mean fewer trips. If you hate refills, moving from 5 lb to 10 lb is a common sanity upgrade.

FAQ

Why is my tank empty in a few days?
Most commonly: a leak, a bad check valve, or a regulator/needle valve that drifts. Do a soap bubble test and confirm your system pressure behavior overnight.
Is a bigger tank always better?
Bigger tanks reduce refill frequency, but they take space and need to be secured. For many people, 10 lb is a sweet spot between footprint and convenience.

Need CO2 locally?

Browse suppliers and filter by refill vs exchange based on what you prefer.

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