How to Set Up an Aquarium CO2 System the Easy Way
When it comes to planted tanks, we always encourage beginners to start with easy, slow-growing plants that only need low lighting and an all-in-one fertilizer. Some plants may be more difficult to grow under water and will require additional carbon dioxide (CO2) and high lighting. Aquarists can inject CO2 gas directly into water using many methods. They have tried many types of equipment, scheduling and dosage amounts. Aquarium Co-Op has tried many and created this guide to help you choose the most reliable and simple method.
Does CO2 get rid of algae? It’s a common belief that CO2 automatically fixes algae problems, but this is not true. A healthy planted tank must have three components in balance – lighting, fertilizer, and carbon dioxide. CO2 is just one of the primary nutrients that plants need to grow. Many beginners use too much light and fertilizer, so adding CO2 can help balance the aquarium. Algae can develop if there is too much fertilizer or high lighting in a tank.
Let’s look at a cookie recipe for an analogy. To make a larger batch of cookies (e.g. greater plant growth), you should add 5x the normal amount of flour (e.g. fertilizer), to your dough. You can make a bad cookie if you only add 5x as much flour to your recipe.
Does every aquarium plant require CO2 injection? All aquatic plants use CO2 for their basic building blocks. While some types, such as cryptocoryne, don’t need extra CO2, other plants like scarlett temple may benefit but won’t. Blyxa japonica is a third type of plant that requires more CO2. This includes dwarf hairgrass, dwarf baby tears, and other carpeting plants.
Materials for a Carbon dioxide System
We will be focusing on the installation and operation of the CO2 system. Get the tools and equipment you need to get started.
1. Aquarium Co-Op CO2 cylinder regulator What is a regulator and how does it work? How can you control the amount of gas that exits the tank’s CO2 cylinder and into the aquarium water? What are the differences between a single-stage and two-stage regulators? A single stage regulator reduces cylinder’s gas pressure by one step. A two-stage regulator decreases the pressure by two steps. This results in a more stable, reliable flow of CO2. Two-stage regulators are also better at preventing “end-of tank dumps,” where a CO2 cylinder that is nearly empty may leak its remaining gas in one step. Is it better to use a DIY or pressurized CO2? We’ve tested many DIY systems that contain yeast and citric acid. However, they are less stable than a pressurized CO2 system with a regulator/cylinder. The DIY reactions often make lots of CO2 at the beginning and then decline over time, and the inconsistent amounts of CO2 can make it difficult to balance a planted tank. The process can be slow and difficult to maintain because the pressure is lower, the temperature can influence the reaction, as well as the time it takes. We can set it up once, and it will run for one- to three years before we have to refill it.
1. Aquarium Co-Op manifold add-ons – You can add up to five additional manifold blocks to your regulator to expand the system or run CO2 to multiple tanks.
1. CO2 cylinder tank Can I use my CO2 paintball tube? The Aquarium Co-Op regulator was not designed for paintball tanks. They are compatible with standard cylinder tank sizes that have the male thread CGA320. – Where can I buy a CO2 cylinder? We like to get ours from local home brewing supply stores and welding supply stores. Usually, they also offer CO2 refill services if you bring back your cylinder when it’s empty. – What size CO2 cylinder should I get? If you are running a high tech planted aquarium injected with high amounts of CO2, people recommend getting the largest size possible so you will not have to refill the cylinder as frequently. For the average customer, however, we recommend a 2.5-5lb. A 5 lb. cylinder is recommended for aquariums up to 20 gallon. A 10 lb. cylinder is available for 25-to-40-gallon aquariums. cylinder for aquariums up to 55-gallon. Scale the cylinder to fit five or six aquariums.
1. Airline tubing, or CO2 tubing, is it necessary? We have never seen any CO2 loss in our aquariums using the Aquarium Co-Op airline tube (a flexible, black, PVC-based tubing) from Aquarium Co-Op. Special CO2 tubing can be more costly, harder to bend and less readily available.
1. Regular check valve or stainless-steel check valve (optional). Do I require a CO2 regulator? Check valves prevent water from flowing out of your aquarium and pouring onto the regulator. The Aquarium Cooperative regulator has a built in check valve. However, you can also add another one to provide additional protection. We have personally used the regular plastic check valves with CO2 systems at our fish store, warehouse, and homes, and they have not broken down. We also offer a stainless-steel version to increase durability, but CO2 can degrade plastic over time.
1. CO2 diffuser Which CO2 diffuser type should I choose? All CO2 diffusers designed for aquariums should operate at around 40-50 psi. – How do I clean a CO2 diffuser if it becomes clogged? Diffusers must be cleaned or replaced at some point because of algae buildup. Because diffusers can be made of different materials, follow the manufacturer’s cleaning instructions to use diluted bleach, vinegar, or other methods.
1. Water or mineral oil – Regular tap water can be used to fill the bubble counter so that you can see the approximate rate at which CO2 is entering the aquarium. Mineral oil can be used in place of water, as the water will evaporate.
Electrical outlet timer 1. Adjustable wrench measuring at least 1.25 inches in width Scissors 3. Spray bottle with water, Dawn dish soap and a few drops
How to Install a CO2 system
Once you have all the equipment, we recommend you follow our detailed manual and video tutorial for step-by-step instructions. To help you visualize the entire CO2 system, this high-level diagram shows how all the parts are connected:
The regulator (B), which screws onto the CO2 tube (A), is shown in Figure 1. The regulator (B), can be upgraded with optional manifold block add ons. – The bubble counter (C) on the regulator is filled with liquid, and airline tubing is attached to the lid of the bubble counter. The airline tubing connects with the diffuser (D), which can be found at the bottom. The optional check valve (E), which can be installed near the aquarium’s rim, is located in line with the airline tube. The power adapter (G) connects to the regulator’s solenoid cable (F). – The power adapter (G) plugs into the electrical outlet timer (H), which plugs into a wall outlet or power strip.
What if the CO2 bubbles emitted from the diffuser get into the aquarium’s water surface? This is normal. It is important to position your diffuser as low in the aquarium as possible. When the bubbles are released from the diffuser, they imperceptibly get smaller and smaller as they rise and the CO2 gas is being absorbed into the water.
Put the diffuser in the aquarium’s base to give the CO2 bubbles more time to dissolve into water.
How Much CO2 Do You Need?
In the manual, we recommend tuning the regulator to approximately 1 bubble per second (i.e., the rate of CO2 bubbles flowing through the bubble counter) because we would rather start with a lighter amount of CO2 to keep the fish safe. That being said, CO2 dosing amounts are different for every tank, and the bubble rate is not a perfect form of measurement since each aquarium has different plant and fish stocking levels. We don’t use drop-checkers to find the perfect CO2 level, but we trust the plants and nature to tell us when they’re happy.
The plants photosynthesise during daylight hours and consume carbon dioxide. They also produce oxygen (O2), and sugars.
The plants can produce enough oxygen if they have enough light and carbon dioxide. You can see tiny bubbles bursting from their leaves if this happens. In our warehouse, we dial the CO2 level on our plant-holding aquariums until we consistently see this “pearling” effect. It takes plants 24 hours to adjust the CO2 level. Therefore, we wait three days to make any changes to the system.
When the water is saturated in oxygen, aquatic plants produce visible bubbles.
When should I turn on and off the CO2 in my aquarium? As mentioned before, plants use CO2 when there is light to photosynthesize. The process is reversed at night, and the respiration cycle takes place, where plants use oxygen and sugars to produce CO2. Therefore, we want to shut off the CO2 regulator when the aquarium light is off. To optimize CO2 use, set the regulator’s timer so that it turns on about 1-2 hours before the aquarium light comes on. The regulator will then turn off approximately 1 hour before the light goes out. (If you only have one timer, you can use the same timer with a power strip so that the light and regulator turn on and off at the same time.)
Is CO2 dangerous for aquarium fish? It can be harmful for animals in large enough quantities if (1) CO2 causes the water pH to drop too quickly or (2) people try to be so efficient with the CO2 that they end up cutting off the oxygen that fish need to breathe. Hobbyists may try to reduce surface agitation in order to limit gas exchange and CO2 escape from the water. However, less gas exchange also means less oxygen will enter the water, which can cause your fish to struggle and gasp for air. Use an air stone or other device to agitate the water surface in conjunction with your pressurized O2 system to increase CO2 and O2 levels. Yes, you may have to increase your bubble rate a little to compensate for the slight loss of CO2, but having enough oxygen for your fish (and plants at night) is more important and can help lead to the pearling effect that is so desired by planted tank enthusiasts.
We wish you all the best with your pressurized CO2 system. We also hope that you enjoy exploring the world high-tech plants. You can find more information about our CO2 regulator on the product page. There is a demo video and a manual.