Pioneering Hydroponics

Since 1976

Hydroponic Glossary


Absorption - Substance uptake into plants. This can be liquids i.e Nutrients or gases such as oxygen.

Adsorption - When substances attach to a surface. Such as foliar sprays etc.

Adult - A plant capable of forming flowering tissues.

Antiseptics - Micro-organism deterring substance that reduce risk of infection when applied to plants.

Aeration - Supplying soil and roots with air or oxygen. Some hydroponic systems create an aerated nutrient solution with the use of an aquarium pump and air stones.

Aeroponic - Such as our Amazon system, roots are consistently or intermittently misted with nutrient solution. See also X-Stream Aeroponic Propagators

Acid - Media or nutrient solution with low pH, below 7.

Alkaline - Media or nutrient solution with a high pH, over 7.


Bloom phase - The period of growth when plants flower.

Buffering - Reducing dramatic pH level variation in a solution.

Bloom / Blossom Booster - Nutrients that are high in phosphorus (P) which increases flower yield.

Burn - Leaf tips brown due to excess nutrients and salt. Causing the plants to burn


Capillary action - The method in which fibres to soak up water.

Carbon Filters – Are used to scrub the air in a grow room of  VOC’s before it leaves the grow room. The absorbency of the carbon draws V.O.C’s in and traps them in its porous body. See Rhino Carbon Filters

Cell - Smallest living organism able to live independently.

Chelate  - Organic structure containing metal element preventing oxydation.

Chlorophyll  - A plants green pigment. Essential to photosynthesis as it captures the photon of light

Clay pellets  - Growing medium of small hard baked clay pellets. See Clay Pebbles

Coco / Coir - Growing media created from the natural fiber of coconut husks. See Coco / Coir

Combination Day Plants – A plant requiring exposure to short day conditions and long day conditions in a particular order to encourage flowering.

Contactor / Relay – Units with the purpose of controlling electrical surges so as to protect electrics from fusing. See Green Power Contactors

Cutting - Asexual propagation of plants taken from the tip containing a meristem as either a terminal or axillary bud.

Carbon Dioxide (CO2) - A colorless, odorless, tasteless gas in the air, essential for plant life. Occurs naturally in the atmosphere.

Chlorosis - Sick plant with yellowing leaves caused by a nutrient deficiency, usually iron or nitrogen.


Dilution - When nutrient solutions are made less concentrated by adding water.

DNA - A structure containing the characteristics of a living organism.

Drainage – Waste water that is removed from a system or re-circulated.

Dampening Off - Overwatering is the main cause of damping-off. This is a disease that effects seedlings and cuttings, causing stems to rot.

Drip Aeration - Watering method that utilises air pressure from an air pump to filter nutrient solution out of a ring of circular feeding ring.

Dripper System - Watering system using a main hose with small water drippers. Water is released from the drippers, one drop at a time. See Dripper Systems


EC - Electric conductivity. Used to measure ion concentration (concentration of salt) in water. See EC Meters

Enzyme - Protein molecules of a very specific function. A catalyst for biochemical reactions.

Ebb and Flood - A system where media is periodically flooded with nutrient solution and then drained, feeding and aerating the media and roots. See Ebb & Flood


Fans and Air movementFans are a vital tool in maintaining a desirable environment for plants. They can be used to maintain negative pressure in a grow room.

Fertigation - Nutrient, or other water-soluble product application through an irrigation system.

Flood and Drain – See Ebb and Flood

Floral Phase – The period when plants is put on floral structures.

Fructification – When a plant forms fruits.

Foliar Feeding - Spraying plants with nutrient solution, absorbed by the foliage.

Fungicide - A formulation that destroys fungus.


Granulates - The size of a dry solution that is not quite powder size as it is slightly larger.

Growing Phase - The period when plants grows. This usually pre-empts the flower stage.

Germination - The development of a plant from seed.


HID Lamps – High Intensity Discharge lamps encompasses a range of Hydroponic lighting such as HPS (high pressure sodium) and MH (metal halide) All produce light spectrums that create a natural environment for plants being grown indoors.

Hormone - A substance that acts on specific organs and cells to effect growth or change.

Hydroponics - Growing plants in nutrient solutions or inert material rather than soil. See Hydroponic Systems

Harden Off - To gradually acclimatize plants harsher environments. Seedling and cuttings need to be hardened-off before going outdoors.

Hygrometer - A measuring tool to monitor humidity in the atmosphere. See Thermo / Hygrometers


Inert Medium – A media form that will not add or take nutrients from feeding solutions. See Grodan

Irrigation - Application of water to soil.


Juvenile – The initial period when a plant is incapable of changing to a flowering form of tissue.


Long Day Plants – A plant that requires a certain length of time with no light that is shorter than the amount of time it is exposed to light, that induces flowers to form.


Metabolism - Biochemical processes that take place in cells in order to sustain life.

Mineral - an inorganic element, such as sodium, zinc, potassium, calcium, or iron, that is essential to the nutrition of plants.

Mycorrhiza - A group of symbiotic fungi that aid root cells in increasing uptake of water and nutrients.

Macronutrients - Primary nutrients N-P-K (nitrogen, phosphorus, and potassium) or the secondary nutrients magnesium and calcium.

Media -  The substrate or soilless material which supports the plant and absorbs and releases the nutrient solution in hydroponic horticulture. See Media

Micronutrients - Also known as Trace Elements, including Sulphur, Iron, Manganese, Boron and Copper.


NFT (Nutrient Film Technique) - Method in which nutrient is fed in a tray in a thin film where the roots take it up. Allowing roots constant contact with both the nutrient and the air layer above. See NFT


Organic Nutrients - Nutrients bound to organic structure


pH - Measures the acidity or alkalinity of a solution. Scale is 1-14. 1 is acidic, 14 is alkaline, and 7 is neutral. See pH Meters

Photoperiod - The amount of time a plant is or isn’t exposed to light

Photosynthesis - A chemical process, created by light. Transforms carbon dioxide from the air into basic organic compounds and molecules used by plants to form sugars

Potting Mix – Media developed for Potting, consisting of organic and inorganic materials

Propagation Medium - Media specially developed for seedlings or cuttings. See Grodan

Perlite - Sand or volcanic glass, expanded by heat. It holds water and nutrients on its irregular surfaces.


Reverse Osmosis - A process in which a very fine filter stops minerals of specific sizes from passing through. This process removes salts and minerals from the water.

R.H.P - A Dutch quality standard for Media. Richtlijn Hollandse Potgronden

Recirculating System - A system that re-uses drainage water. See Hydroponic Systems

Rockwool - An inert media made of basaltic rock produced by a melting process into fibres. See Grodan

Run to Waste - A system that does not re-use drainage water instead it flows away.

Reservoir - A hydroponic system container which holds nutrient solution.


Short Day Plants – A plant that requires a certain length of time with no light that is longer than the amount of time it is exposed to light, that induces flowers to form.

Substrate – Growing Media that enables roots to grow and the plant to stand up.


Trace Element - Elements that must be in nutrients of an organism for growth. Only a small quantity of trace elements are required

Trichoderma - Group of related fungus. Good Trichoderma protect the plant against harmful fungi. There are also 'bad' Trichoderma that eat beneficial fungi.


V.O.C (Volatile Organic Compound) - are organic chemicals that have a high vapor pressure (scent) at ordinary room temperature.


Wick - Using a wick suspended in nutrient solution. Nutrients feed up through the wick and are absorbed by media and roots. See Quadgrow