Two-stage CO2 regulators have been the topic of great debates. Some argue that single stage regulators are just as effective at improving the utilization of CO2 dosing, while others simply need clarification because of conflicting information online. Regardless of whether you plan to purchase a setup, or build one yourself using a bubble counter, solenoid, and needle metering valve, there is a multitude of considerations that must be made in order to successfully implement a CO2 regulation system that will properly aid in caring for your planted aquarium.
In order to comprehend how and why dual stage regulators are so beneficial, you must first understand how they differentiate from single-stage regulators. Dual-stage CO2 regulators use two steps to lower the source pressure down to the delivery pressure that is specified by the control gauge. Each step utilizes a diaphragm, control valve, and spring. During the first stage, the inlet pressure is decreased three times the amount of the maximum pressure. During the second stage, the final reduction of pressure occurs. The benefit of having these two separate stages of reduction is that the pressure is still constantly delivered, in spite of the inlet pressure reduction.
The “decaying inlet characteristic” that single stage regulators exhibit under these conditions is the result of the reduction of inlet pressure while the delivery pressure increases, and eventually emptying the cylinder.
With two stage regulators, the second stage serves as compensation for the increased pressure which works to maintain a constant stream of pressure without regard for the conditions of the inlet pressure. In situations that involve the critical need for a consistent supply of gas, as in the case of gas delivered to analytical machinery, dual stage regulators are essential.
Single-stage regulators go through the exact same process, except it uses a singular increment reduction of the source in order to release pressure. But it is because there is only one step involved that it is difficult to control the pressure outlet accurately because of the decaying of the source pressure.
The only recommended circumstances that would merit a single stage system is when you can keep track of and control the CO2 regulator whenever an adjustment is needed, or in the case where the regulator is capable of providing a constant supply of pressure.
The pressure supply is not the only significant considerations of differentiation between the two regulators. The droop is also important, as it is the variance in delivery pressure between the range of the maximum flow capacity and flow level zero. The delivery pressure, in most cases, will increase as the inlet pressure decreases.
This means that the difference between the two is the droop and pressure supply characteristics. With single stage regulators, there is less droop involved when considered across the spectrum of flow rates, but there is an extreme effect of fluctuation regarding the supply pressure. On the other hand, the benefit of a two-stage regulator is the minimal effect on the supply pressure, but it does display a larger effect on the droop. A steep droop is useful for avoiding a shift in the baseline of chromatographs, or the separation of gas and liquid in order to mobilize the gas. That is the main reason why most people prefer dual stage regulators to single stage set-ups. The most beneficial aspect of a dual-stage regulator is that CO2 is prevented from being dumped into the tank in the case that the canister is nearly depleted, which would result in imminent fish catastrophe.
The monitoring and adjusting of CO2 levels are critical to the survival of plants and fish, whose living habitat is a planted aquarium. In fact, the biggest reason people accidentally kill their fish- more than any other factor- is because of insufficient CO2 levels. Regardless of whether the levels are too high or too low, CO2 is a fundamental chemical compound that dictates the success of the aquamarine project and must be delicately monitored. Ideally, the level of CO2 in your tank should initially be between 30 and 40 ppm. Without proper monitoring and adjustments, even though it can seem complicated to balance at first, you could experience large amounts of algae accumulation because of the level of dependency on CO2.
CO2 (Carbon Dioxide) is made up of two oxygen atoms that are bonded to a singular carbon atom. During the process of photosynthesis, the plants in the aquarium absorb the water and CO2 from the environment, combine them with the energy of light in order to produce oxygen as well as sugars, The oxygen that goes free turns into a gas and is released at the surface of the tank. But even though the oxygen molecules are expelled, oxygen is still required in order to maintain the balance of the aquarium and must be readily available in order for plants and fish to absorb dissolved oxygen in the water.
If there is not enough oxygen in the water, it will become stagnant and then a deficiency of oxygen becomes a eutrophic situation. This condition allows for organic wastes and rotting materials to contaminate the water at a higher-than-normal concentration, resulting in rapidly dying fish and algal blooms. That is why surface ripples are very important for O2 balance within the tank. The surface ripples re-oxygenate the water by replacing evaporated O2 and ensuring the concentration levels remain within a normal range.
The Hydrogen from lighting generates chemical energy that is used to form glucose (sugar). The plants consume the sugars in respiration, utilizing the compound to produce complex carbohydrates that the plants can use as a food source to help them grow and develop. The CO2 regulators introduce and balance CO2 levels along with the aquamarine ecosystem. Using regulators help guide a successful aquascaping system that will thrive.
If you plan to build your own CO2 tank, there are a few essential materials that you need. First and foremost, the type of metals you choose to use for all of your parts will depend on the compatibility of the metal with the gas. Aluminum, PCTFE, Teflon and stainless steel are universal, meaning they work equally well for corrosive and noncorrosive types of gas. However, Brass, Nylon, and Neoprene work best for noncorrosive gases. Monel and Nickle are typical materials for corrosive gases.
Dual-stage regulators have two gauges: an inlet pressure gauge that is also the cylinder, as well as the outlet pressure gauge that is referred to as the delivery gauge. When the system is being set up, the cylinder pressure gauge will be adjacent to the inlet port, while the delivery gauge will be situated adjacent to the outlet port.
The next step involves fastening one of two types of specialty gas regulators. If the regulator is attached with a Compressed Gas Association fitting, then the cylinder regulator is sufficient. In the other instance, the regulator is connected to an extra line that empowers you with additional measures of pressure control. Once assembled, use valves to control the flow of gas, while ensuring the delivery pressure meets the 25-90% pressure range and establishing the initial pH, kH and gH levels.
Do not confuse kH, pH, and gH, with each other, nor misunderstand their relationship with one another. The pH level is the measurement of acidity or basic properties in the water and should be maintained at 6.6. The kH measures the alkalinity in the water. The kH should be between 19 ppm to 38 ppm and adjusted prior to the pH in order to stabilize.
Adjusting the pH before establishing the kH level will not garner the same results. The gH is a booster for the kH, measuring the general hardness of the water quality, and the concentration of essential minerals such as calcium and magnesium. The gH exposes how much of these minerals are stored up for the balance of aquatic life, and should take precedence over the Kh.
When it comes to getting the tank started with a CO2 setup, aim for at least a 1ph drop in order to start getting near 30ppm of CO2. Ideally, a pH drop of 1.2-1.5 will work if there is a high enough concentration of oxygen in the aquarium, which can be created by surface movement and ripples that can be accomplished with the use of a pump.
Now that you understand the function, purpose, and benefits of dual-stage regulators, as well as how to set one up. Implementing your own rig helps understand each phase in the process. You will be able to easily and effectively maintain the droop and release of pressure. Not only will your ecosystem thrive, but you will also avoid unintentionally killing your fish in the case that the canister is depleted and run the risk of dumping high concentrations of CO2 into the tank, which is the biggest benefit of all.
