Includes flow regulator, needle valve, electronic solenoid & bubble counter. Unit comes with dual gauges each with dual reading of both psi & kg/cm. Left gauge meters tank capacity and right gauge meters flow. Needle valve flow control provides for precise measurement. The solenoid valve comes with a 1.5 meter power cord. (CO2 bottle is not included)

Includes flow regulator, dual gauges, needle valve and electronic solenoid
Corrosive resistant chrome plating
Automatic CO2 control for planted freshwater or saltwater reef tank
Works with any pH controller

Full-featured safety regulator with independent needle valve

Designed specifically for aquarium use, the Pressure Regulator and Needle Valve are independent units connected by low-pressure CO2 tubing. The high precision needle valve is designed to be mounted on the side of the aquarium enabling easy access for regular flow adjustment or complete shut off. Once assembled and set to the desired working pressure the CO2 Cylinder/Regulator can be located out of site, behind or under the aquarium. Easily upgradeable for automatic control with an in-line solenoid control valve.

Easy to read high and low pressure gauges
Integral pressure relief valve
Independent needle valve -- Stable flow rate from 4 bubbles per minute

Mounts inside the tank for permanently checking the CO2 level in aquarium water.

The uniquely designed CO2 Reactor 500 was created for a wide range of planted aquariums. Compact in size, the reactor will efficiently dispense CO2 while not taking away from the natural beauty of the the aquarium. A highly effective vortex reaction chamber ensures almost complete dissolving of available CO2 while allowing other gases to be vented to the water surface. Suitable for 10 to 125 gallon aquariums

This bottle does not contain CO2. It's shipped empty and must be filled locally

Compact Bubble Counter with an integrated check valve.
Provides an accurate measurement of gas flow rate
Check valve protects gas equipment from back siphoning
Easy to read -- Compact design

The Red Sea CO2 Pro System is a complete, efficient and user-friendly system to maintain a desired level of CO2 in planted aquariums from 10 to 125 gallons.

The CO2 Pro System contains the following components:
Full featured, dual gauge, safety Regulator that is supplied in versions suitable for connection to standard refillable CO2 cylinders, disposable CO2 cylinders and "Paintball? CO2 cylinders (USA only).
Independent, high precision, in-line, Needle Valve that can be located in a convenient location on the side of the aquarium and be set to stable flow rates as low as 4 bubbles per minute. Highly efficient CO2 Reactor 500 that includes an adjustable flow water pump and can dissolve over 180 bubbles of CO2 per min
Bubble Counter with integrated check valve
Real time CO2 Indicator
Does not come with CO2 bottle (available on this page) or tubing

Same description as the Red Sea CO2 Pro System, but also comes with a Solenoid Valve

The Reactor 1000 is a hermetically sealed unit for introducing CO2 into large aquariums. It is externally mounted and can be used with aquaria up to 500 gallons. 15” x 3”.