The UNS Pro CO2 Dual Stage Regulator is designed for hobbyists looking for a long-term, professional-grade CO2 solution for planted aquariums. Featuring dual gauges for monitoring both working pressure and remaining cylinder pressure, it makes it easy to track CO2 levels and anticipate when a cylinder is running low. Included manifold blocks allow a single CO2 cylinder to supply multiple planted aquariums, making the Pro Regulator an ideal choice for expanding aquarium collections, fish rooms, and advanced aquascaping systems.

Best For
- Medium to large planted aquariums
- Long-term CO2 systems
- Hobbyists using refillable CO2 cylinders
- Multi-aquarium setups
- Aquascapers looking for more control and consistency

Why Choose the UNS Pro Regulator?

Dual-Stage Reliability: Dual-gauge regulators are sometimes referred to as dual-stage thanks to an extra fail-safe stage that prevents “end-of-tank dump” (a sudden release of CO2 when a cylinder is running low). This built-in feature keeps CO2 levels more stable and helps prevent sudden fluctuations.
Expandable for Multiple Aquariums: The included bubble counter manifolds allow CO2 to be distributed across multiple planted aquariums from a single cylinder. Additional manifolds can be added as your aquarium collection grows (we recommend up to 8 splits).
Compatible with Standard Refillable Cylinders: Designed for use with CGA-320 CO2 cylinders ranging from 2.5LB to 20LB, providing a practical long-term solution with fewer refills and lower operating costs compared to disposable options.
Beautiful Design: Finished in an anodized Space Grey, the Pro Regulator offers a clean appearance that complements planted aquarium equipment and cabinetry.

The UNS Pro Dual Stage Regulator is intended for hobbyists ready to invest in a dedicated pressurized CO2 system. While larger than cartridge-based alternatives, it offers greater stability, longer refill intervals, and the flexibility to expand over time.

Product Compatibility
- Standard CGA-320 CO2 cylinders (UNS Pro Cylinders)
- CO2-proof tubing
- Aquarium diffusers
- Inline diffusers
- Bubble counters

What’s Included
- UNS Pro CO2 Dual Stage Regulator
- CGA-320 Adapter
- 2 Bubble Counter Manifolds
- Power Adapter
- Assorted O-Rings (extra replacements included)
- Installation Tools

Learn about other CO2 regulators and find the best solution for your planted aquarium. Shop All CO2 Regulators