Episode 15: Carbon, Oxygen, and Hydrogen in Aquaponics
This episode is the first in a four part series about aquaponic nutrients.
Today we’re talking about carbon, nitrogen, and oxygen. “Wait a minute!” you’re thinking, “Those aren’t plant nutrients.” Actually, they are- but no one talks about them. Why? We’re about to find out.
Regardless of how carbon enters your system, it will eventually take the form of CO2, the most interactive form of carbon in aquaponic systems.
CO2 is essential for plant growth. Plants use carbon dioxide to produce sugars, which it uses to make a variety of carbohydrates for different applications. (Turning CO2 into a carbohydrate is called fixing CO2.)
CO2 is important to microbes carrying out nitrification.
Carbon enters the system as carbohydrates in fish food, or as CO2 in the atmosphere.
The use of CO2 by algae can cause diurnal swings in pH, because it consumes CO2 (which in water is a weak acid) only part of the day.
Aerobic organisms function in the presence of oxygen and need it to live. (The opposite of this is anaerobic, and not good to have in an aquaponic system.) Oxygen is especially important in root zones.
Temperature and oxygen solubility are inversely relates; the higher the temperature, the less soluble oxygen will be in the water, and the lower your DO (dissolved oxygen) will be.
Oxygen is also in the air and is produced by the plants.
Hydrogen enters your system almost entirely as water. Plants are able to split water molecules and use the constituents to make a variety of products, including carbohydrates.
Carbon, oxygen, and hydrogen aren’t discussed as much as much as some of the other nutrients, like potassium of magnesium. Maybe this is because we have to do more troubleshooting with other nutrients while these three are already “built in” to our systems. Regardless of the reason, it’s important to think about carbon, oxygen, and hydrogen because they are core elements to our system.
Thanks for joining us today! Stay tuned for more on nutrients in aquaponic systems.