Review on 🐠 FZONE Pro Series Aquarium CO2 Regulator with Dual Stage, Adjustable Output Pressure, DC Solenoid, Integrated High Precision Needle Valve, and Bubble Counter by Sohini Ledesma

I've been an aquarist for decades, but this is the first time I've attempted CO2 injection in a planted aquarium. I have a 55 gallon freshwater tank that is heavily planted and moderately stocked with fish. I have adequate lighting and fertilizer in the aquarium, but I need a carbon source to encourage plant growth. After extensive research into various options, I settled on CO2 injection from a standard 5# CO2 tank, FZONE regulator and ceramic diffuser. I chose the FZONE Pro two-stage regulator for a number of reasons.1. This regulator comes with a standard CGA320 fitting that screws onto standard CO2 tanks like the 5# tank I chose. If you want to use this regulator with small tanks such as paintball tanks, soda stream tanks or disposable tanks, adapters are available. However, for a tank of 55 gallons or larger, standard CO2 cylinders are more economical.2. The regulator is supplied with two control stages and two pressure gauges to monitor tank and supply pressure. In addition, the supply pressure is adjustable. The two stage regulator maintains a constant supply pressure and eliminates the possibility of CO2 release at the end of the tank which could harm the animals in the tank. So I don't have to check the tank pressure every day. Many regulators come with two gauges, but they represent only one level of regulation. Some mini-regs only have one gauge. Some regulators are shipped with non-adjustable supply pressure.3. The controller comes with a solenoid that operates on a 12V DC power supply. It is safer than a 120V solenoid when you work near water. If the power supply fails, it is easy to replace as 12VDC power supplies are commonly used for a variety of applications. I have a power supply hooked up to a timer so the CO2 turns on 2 hours before my morning lights and turns off 1 hour before the lights go out. This ensures that the plants have enough CO2 during their active growth phase, but does not accumulate excessive CO2 at night when the plants cannot consume it. The solenoid completely blocks the flow of CO2 when the power is turned off.4. The regulator comes with two needle valves, not one, and corresponding bubble counters with built-in check valves. They appear to be precision valves that allow precise control of the flow of CO2. They seem to be fairly stable in the sense that when CO2 is turned on in the morning the flow rate is the same as the day before. I'm set at around 90 bubbles per minute, but you may need more or less depending on the size of your tank, water chemistry, and plant requirements. I only use one of the needle valves, but you can connect a second tank or reserve it as a backup in case the first one fails. The check valve ensures that water from the tank does not enter the needle valve and regulator when the CO2 flow stops at night. This avoids a potential maintenance problem.5. When I filled the CO2 tank, the supplier provided a couple of nylon washers. However, I found these washers were not thick enough to ensure a good seal between the tank and the regulator. The thicker washer that came with the regulator worked great.6. I haven't had the unit long enough to be sure it will last, but since I only have to top up the CO2 tank every 4-6 months and don't have to do any routine needle valve adjustments, I'm confident the system will last. The most likely maintenance issues are the solenoid and power supply; both are easily interchangeable if necessary.7. Finally, the system appears to be fairly valued. Most two-stage regulators are significantly more expensive than the FZONE. Having not used CO2 injection before, I didn't want to spend $200-$300 just on a regulator. I recommend this unit to anyone with a 40 gallon or larger tank looking to get started with CO2 injection. For tanks under 40 gallons, this is probably more than needed, but it's fine for my 55 gallon setup.