When to change my Co2 cylinder.

[Filet-O-Fish]

I took this pix of my Co2 regulator gaues this morning. Can the members here tell when is the time to change to a new Co2 tank.

I know A refers to working pressure, so how can I use B to know the balance?
Thanks.

[Urban Aquaria]

When the Co2 tank is full, the main gauge should be around 900-1,100 PSI (it will stay at those levels while the Co2 is still in liquid form)... yours is now around 400 PSI, which indicates the Co2 is probably now in gas form. From my experience, at that pressure level there should be around 10%-20% of usage left. You will notice the pressure dropping faster from there on.

You could still use it for a while more (depending on your injection amount), though it would be a good idea to get it re-filled soon to avoid running completely out of Co2 without notice.

[Jimmy]

Best is to have 2 tanks, one on standby. So no downtime at all.

[Filet-O-Fish]

Best is to have 2 tanks, one on standby. So no downtime at all.

Yup I do have two 5 litres tanks. I refill at NA or do 1 to 1 exchange for $19.

[Filet-O-Fish]

When the Co2 tank is full, the main gauge should be around 900-1,100 PSI (it will stay at those levels while the Co2 is still in liquid form)... yours is now around 400 PSI, which indicates the Co2 is probably now in gas form. From my experience, at that pressure level there should be around 10%-20% of usage left. You will notice the pressure dropping faster from there on. You could still use it for a while more (depending on your injection amount), though it would be a good idea to get it re-filled soon to avoid running completely out of Co2 without notice.

I think I better change tomorrow as I don't want a gas dump before the tank finishes. I'm waiting for an update from Vinz so that I can order the 2 stage regulator from UK.
Is there any relation to the working dial now at 55psi relate to an emptying tank?
Cheers.

[Urban Aquaria]

I think I better change tomorrow as I don't want a gas dump before the tank finishes. I'm waiting for an update from Vinz so that I can order the 2 stage regulator from UK.
Is there any relation to the working dial now at 55psi relate to an emptying tank?
Cheers.

The working pressure will usually still stay at around 55 PSI while the main tank pressure is still above that value... but if the main tank pressure starts dropping below 55 PSI, the working pressure will also follow and drop alongside it too.

[Filet-O-Fish]

The working pressure will usually still stay at around 55 PSI while the main tank pressure is still above that value... but if the main tank pressure starts dropping below 55 PSI, the working pressure will also follow and drop alongside it too.

Thank you so for the reply. Now I understand the way these dials work.
Cherrs.