What scale for monitoring co2 remaining?

[Little]

Hello all

I have a single stage co2 supermarket nano regulator using the nano cylinders.

I would like to set up a weight system to ensure I replace the tank before it is fully discharged to reduce the chance of the tank “dumping” and harming the livestock (Cherry shrimp tank).

Weighing the tanks before use is simple. But… what are people using to weigh during use?

Hanging or standard? Digital or mechanical?

 

[Zeus.]

@ian_m weighs his cylinders to monitor CO2 left in cylinder, I am pretty sure he uses digital scales.