AquaZilla

Aquarium Plant Nutrition
Plants contain chlorophyll which absorbs light. The light energy converts carbon, hydrogen and oxygen into sugars, starches and cellulose. These are called carbohydrates and this is how plants store the energy derived from light. The process is called photosynthesis.
Oxygen (O), carbon (C), and hydrogen (H) are obtained from water (H2O) and carbon dioxide (CO2). These are absorbed by the plant through the roots and through the leaves. Without them the plant will die.

In addition plants require other essential elements – nitrogen for amino acids to make protein, magnesium is required to make chlorophyl and so on.

These elements can be divided into two groups:-

Macronutrients. These are nutrients required by plants in relatively large amounts. They are: nitrogen (N), phosphorous (P), potassium (K), magnesium (Mg), calcium (Ca) and sulphur (S)
Micronutrients. These are nutrients required by plants in relatively small amounts – sometimes referred to as trace elements. These include iron (Fe), manganese (Mn), copper (Cu), Zinc (Zn), boron (B), molybdenum (Mb) and chlorine (Cl)

In the natural world these elements are usually found in the soils or sediments in which the plants are growing.
In the artificial world whether it’s a plant in a pot on the windowsill or a plant in an aquarium it is unlikely that there will be sufficient quantities of the elements for the plant to grow well and it will be necessary to add nutrients to ensure that plants survive and thrive.

The nutrients have to be added to the planted tank in a manner in which they can be taken up by the plants. It is not a case of adding the simple elements. It is usually done by adding a fertiliser which has been formulated for aquarium use. This will contain the elements in a form that can be absorbed by the plants. Fertilisers are available in liquid, pellet and powder forms and with different formulations. For example some are available with no added nitrogen or phosphorous for use in tanks with a high fish population.

Proprietary liquid fertilisers are possibly the easiest to use but they can be expensive. Many planted tank enthusiasts make up their own stock solutions from basic chemicals or ‘straight fertilisers’ as they are sometimes called – this is much more economical than buying liquids even if it is more time consuming.
Chemicals that are normally used for this are: potassium nitrate, potassium phosphate, and potassium sulphate. These provide nitrogen, phosphorous and potassium. To provide the micro-nutrients trace element mixes are available and together with magnesium sulphate for magnesium stock solutions can easily be made up.

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