Thank you for your enquiry, yes we still fill Co2 extinguishers for aquarium use the Cost is £5.00 + vat (£6.00)
We should be able to refill whilst you wait.
You are partly correct in that we cannot fill a cylinder over ten years of age until it has been retested, the test will require that the valve be changed as well so we offer tested, refurbished cylinders c/w new valve at £40.00 + vat (£48.00)
We should be able to get one made up for you very quickly but would need to check your current unit to see if a diptube is fitted.
If a diptube is fitted this means that the Co2 liquid is drawn up which is at a higher pressure (without a diptube just the vapour is drawn off at a much lower pressure).
If you have any questions please do not hesitate to contact us again.