Hydrogen, Oxygen & Carbon

Hydrogen, Oxygen & Carbon

Hydrogen, oxygen and carbon are essential for the building blocks of life, they are considered non-mineral elements.

They are also the three most used elements by plants. 

So, what do they do? 

Plants receive Hydrogen via photosynthesis, they receive oxygen via the conversion of CO₂. Carbon Dioxide is broken down into carbon and is used by the plant for energy which is what forms proteins and carbohydrates.

Only small amounts of Oxygen are actually used by the plant the rest is expelled into the atmosphere as excess.

If plants however cannot maintain water stores and have a low turgor in their leaves, the stomata will close which inhibits photosynthesis from taking place.

All of the air we breathe has been cycled through plants via photosynthesis, “Life’s Grand Device”



  • Builds sugars/glucose
  • Respiration
  • Helps propel the ‘electron transport chain’
  • Hydrogen is abundant in our atmosphere



  • Used in conjunction with nitrogen for the process of denitrification
  • Can interact and oxidise other elements
  • Plants do not intake Oxygen from the atmosphere
  • Plants absorb Oxygen via the breakdown of CO


Oxygen is a essential element for plant life and growth, although only a small amount of oxygen is required, it's required in to the root of the plant, as it is also excreted via the stomata in the leaves as part of their absorption process of CO2. This is also why you must use a air stone and air pump in pure Hydroponic water-based systems to supply additional oxygen where there is not enough present in water.



  • Energy source & stomatal operation
  • 50% of all dried plant matter is Carbon
  • Builder of sugars, starches, lignin and proteins


Manures & animal waste are a great source of organic carbon

Carbon gases, in the form of Carbon Dioxide (CO), are absorbed by plants through their stomata on the underside of their leaves, allowing oxygen to leave the plant when absorbing CO.

CO has many significant beneficial effects on plants growth, when paired with excess or high light levels, will increase plant growth and yield significantly as a result. Supplementing CO into grow rooms or greenhouses can be a costly and difficult task for small hobby growers, but definitely a very effective way to increase your plant growth, size and yields. CO requires its own tutorial topic which will come in the next few weeks!

Finally, to come full circle, through many biochemical processes, photosynthesis and others, plants convert and combine all three of these elements together, Carbon (C), Hydrogen (H) and Oxygen (O) to make carbohydrates (CHO) which are used as a stored energy source for plant growth. Carbohydrates are a lengthy topic for another day!



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Other Tutorials

Coco Dry Back
Mendelian Law, The Theory of Inheritance
Botanics and Hydroponics Literature
Light Conversions and Smart Phone Light Meters
Breeding Hybrids: Hybridization

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