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.
Acid – Media or nutrient solution with low pH, below 7.
Alkaline – Media or nutrient solution with a high pH, over 7.
B
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.
C
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.
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 auxillary 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.
D
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.
E
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 Systems.
F
Fans and Air movement – Fans 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 – A system where media is periodically flooded with nutrient solution and then drained, feeding and aerating the media and roots. See Flood & Drain Systems.
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.
G
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.
H
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/Hydgrometers.
I
Inert Medium – A media form that will not add or take nutrients from feeding solutions. See Grodan.
Irrigation – Application of water to soil.
J
Juvenile – The initial period when a plant is incapable of changing to a flowering form of tissue.
L
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.
M
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 Growing Media.
Micronutrients – Also known as Trace Elements, including Sulphur, Iron, Manganese, Boron and Copper.
N
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.
O
Organic Nutrients – Nutrients bound to organic structure.
P
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.
R
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.
S
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. See Growing Media.
T
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
V.O.C (Volatile Organic Compound) – are organic chemicals that have a high vapor pressure (scent) at ordinary room temperature.
W
Wick – Using a wick suspended in nutrient solution. Nutrients feed up through the wick and are absorbed by media and roots.