The Ultum Nature Systems CO2 Pro Cylinder is available in four popular sizes: 2.5LB, 5LB, 10LB, and 20LB. These planted tank cylinders can be conveniently refilled at most local gas or brewery supply shops. Before use, make sure your Pro Cylinder has been properly filled by a licensed professional and that the main valve is fully closed. Next, install your regulator (We recommend the UNS CO2 Pro Regulator). Ensure all regulator valves are securely closed, including any installed UNS Manifold Block(s).

Once everything is securely connected and set to a closed position, open the Pro Cylinder valve fully. Set the regulator main valve to ~35psi and adjust the needle valve on the UNS Manifold Block according to your aquarium's needs. After setup, you won’t need to adjust the cylinder valve again until the CO2 is depleted and the regulator pressure gauge reads 0psi.

CO2 reserves and depletion rates will vary based on several factors, including usage, aquarium plant requirements, and tank size.
Features and Specifications
2.5LB
Volume: 2.5LB / 1.68L
Working Pressure: 139BAR / 2015PSI
Test Pressure: 232BAR / 3364PSI
Height: 11.02" / 280MM [without valve]
Weight: 3.86LB / 1.75KG
Material: DOT3AL Certified

5LB
Volume: 5LB / 3.35L
Working Pressure: 124BAR / 1800PSI
Test Pressure: 207BAR / 3000PSI
Height: 14.53" / 369MM [without valve]
Weight: 6.61LB / 3KG
Material: DOT3AL Certified

10LB
Volume: 10LB / 6.7L
Working Pressure: 124BAR / 1800PSI
Test Pressure: 207BAR / 3000PSI
Height: 16.93" / 430MM [without valve]
Weight: 13.22LB / 6KG
Material: DOT3AL Certified

20LB
Volume: 20LB / 13.4L
Working Pressure: 124BAR / 1800PSI
Test Pressure: 207BAR / 3000PSI
Height: 23.62" / 600MM [without valve]
Weight: 23.80LB / 10.8KG
Material: DOT3AL Certified