Hiwi CO₂ Set Advanced Compact Double Stage

The CO₂ Set Advanced Compact Double Chamber combines the space-saving design of the Compact series with the added stability of a double-chamber pressure regulator. It includes a Hiwi Double-Chamber Pressure Regulator with integrated solenoid and check valve, a CO₂ high-pressure hose (PUR, crystal clear, 3 m), an Orb Checker Nano, the CO₂ indicator solution CO₂ Check (20 mg/l, 250 ml), a bubble counter, and a Neo CO₂ Diffuser Original (Mini, Medium, or Large). This set provides precise CO₂ regulation that remains consistent even with fluctuating cylinder pressure, making it ideal for demanding aquarium layouts with limited space.

The high-quality Hiwi Double Stage Pressure Regulator with SV & CV is used to reduce the pressure of approx. 54 bar within the gas cylinder to a working pressure of approx. 1 to 3 bar (maximum working pressure 3 bar). By combining the working pressure manometer and the cylinder pressure manometer you can regulate the CO₂ supply very precisely and you know at once when it is time to refill the cylinder. The integrated fine needle valve allows a very precise regulation of the CO₂ supply for the aquarium. Thanks to the double chamber system, the working pressure remains constant until the cylinder is completely empty.
When pressure regulators without a double chamber system are used the working pressure may rise relatively fast and abruptly as soon as the gas filling inside the bottle goes below around 20 % of the nominal filling quantity. If you do not re-adjust manually in such a case, the amount of CO₂ supplied to the tank will increase significantly and surmount the dosage that was originally set. If you do not want to take on this task, the remaining 20 % of CO₂ would need constant adjustements of the working pressure. With this double-chamber pressure regulator, on the other hand, the cylinder can be emptied almost entirely without the need to adjust the working pressure for the last 20 % of CO₂, which is of advantage especially when you use large CO₂ cylinders. In a 10 kg cylinder, e.g., around 2 kg of CO₂ would need constant adjustments regarding the working pressure.
This pressure regulator features a space-saving and permanently integrated solenoid valve as well as a built-in check valve. The solenoid valve is directly connected to the pressure regulator, ensuring precise control of the CO₂ supply while requiring minimal space. The integrated check valve reliably protects the entire CO₂ system from backflow of water into the pressure regulator, enhancing the system's safety and durability. The compact design also ensures easy installation and optimal functionality.

The CO₂ high-pressure hose made of polyurethane is food-safe, absolutely crystal clear and without labeling. While PUR hoses are durable, they are not ideal for connecting to glassware. To ensure secure connections, the hose should be softened in very hot water before attaching it to fittings. Similarly, reheating the hose with hot water or a lighter before removing it from glassware reduces the risk of glass breakage.

The Aquasabi Bubble Counter is a valuable tool for monitoring CO₂ levels in aquariums. By counting bubbles over a set period, it allows for a rough estimation of CO₂ being supplied. The Bubble Counter has an integrated non-return valve whose main purpose is to prevent the backflow of aquarium water through the bubble counter into the technical system, such as the pressure reducer, especially when the supply pressure drops.
Using the bubble counter is simple and straightforward. The bubble counter is inserted into the system for optimized control of the amount of CO₂ supplied. The screw thread on the underside of the bubble counter is precisely manufactured to ensure a reliable connection with other components.

The CO₂ Drop Checker (Orb Checker Nano) allows for optimal monitoring of CO₂ levels in aquarium water. The Aqua Rebell CO₂ indicator solution included in the set changes colour based on the CO₂ concentration. Green indicates an ideal CO₂ level of 20 mg/l, blue signifies low CO₂, and yellow warns of excessive CO₂ concentrations.

The AQUARIO NEO CO₂ Diffuser Original is a compact acrylic CO₂ diffuser that efficiently atomises CO₂ through a specialised ceramic membrane, ensuring it dissolves effectively in water. It might be helpful to soak the diffuser in water for about 10 minutes before initial use to displace any trapped air. This could be particularly beneficial during the first 24 hours after installation to minimize the formation of larger bubbles at the bottom edge of the ceramic membrane. Alternatively, one could simply wait after connecting it to the CO₂ system, as the CO₂ will eventually displace the remaining air on its own.

• The pressure regulator is designed for returnable cylinders
• Thread: W21,8 x 14G
• Seal included
• The thread is made according to UK, Europe, Japan and Taiwan standard (BS341 / DIN477 / W21.8)
• The connection for the CO₂ tubing is equipped with a metric thread (M6)
• High-quality solenoid valve with low energy consumption. The solenoid valve is firmly attached to the pressure regulator.
• 1,5 m power supply cord with German plug
• With German instructions of use
• Suitable replacement seal Hiwi seal hard
• 3-metre high-pressure hose for flexible installation
• Hose pressure-resistant up to 11 bar
• Hose bending radius: 20 mm
• Aquasabi Bubble Counter with integrated check valve to prevent backflow of water during pressure drops
• Aquario Neo CO₂ Diffuser Original available in sizes suitable for different aquariums
• Convenient Orb Checker for easy CO₂ monitoring
• Aqua Rebell CO₂ indicator solution with colour change at 20 mg/l CO₂

It is important to note that all components of the Hiwi pressure regulator have been glued together by the manufacturer. They cannot be unscrewed without causing damage. Removing the needle valve will void the warranty. An exception is the hose connection on the fine adjustment valve. This connection is not glued due to the fine thread, allowing for replacement of the hose connection if defective, rather than the entire fine adjustment valve.

Please use the pressure reducer only after reading the operating instructions, which are linked above.

• Make sure that you really start the pressure reducer with a CO₂ bottle.
• Turn the working pressure adjustment screw (operating instructions 4) counterclockwise.
• Close the fine needle valve (operating manual 5) by turning it clockwise. CAUTION: Tighten only slightly!
• Position the pressure reducer so that the pressure gauges are facing upwards.
• Fasten and tighten the pressure reducer to the CO₂ cylinder using the union nut (operating instructions 7).
• It is essential to ensure that the seal is correctly seated and that the sealing surfaces are clean. If the seal is is damaged or lost, please replace it.

The Hiwi Fixed spanner 30 mm is most suitable for the installation.

If algae accumulate on PETG items, it is time to clean them. Cleaning is not difficult but should be done thoroughly. Afterwards, the PETG will shine like new again.

• Use regular household chlorine cleaner (hygienic cleaner) without added fragrances. Always follow the manufacturer’s safety instructions when handling chlorine bleach.
• Pour some chlorine cleaner into a container and mix it with 50% water. Ensure there is enough solution to completely submerge the PETG item.
• Immerse the PETG item in the solution for ½ to 1 hour (depending on the level of dirt).
• Remove the PETG item and rinse it thoroughly.
• At this point, all dirt should be gone, and the PETG item will shine like new again.
• Warning: Do not mix chlorine with vinegar! This creates a life-threatening hazard!

• 1x Hiwi Pressure regulator + SV & CV
• 1x Seal for Hiwi pressure regulator
• 1x CO₂ high-pressure hose (PUR, crystal clear, 3 m)
• 1x Orb Checker - Nano
• 1x CO₂ Check - 20 mg/l (250 ml)
• 1x Bubble Counter
• 1x Neo CO₂ Diffuser - Original (Mini, Medium, or Large)