Questions? Feedback? powered by Olark live chat software

Hydroponics Glossary

Hydroponics Glossary

Aeration—The process of providing soil and roots with air or oxygen. One suggestion is to use Geolite, a medium which has excellent aeration. It’s also possible to get your nutrient solution aerated by the output from the aquarium pump. 

Acid—If the medium or the nutrient solution has a low pH low then an acidic solution will have a pH below 7.

Aeroponics—A growing system where the roots of a plant are either occasionally misted with tiny droplets of nutrient solution, or they’re continually misted with the nutrient solution.

Alkaline—When a nutrient solution has a medium or high level pH of over 7.

Bloom Booster, Blossom Booster—A type of fertilizer that is high in phosphorus so that it can increase its flower yield.

Boron (B)—While not fully understood, it’s believed that the element boron aids in carbohydrate transport.

Burn—Leaf tips can become burned from excess salt or excess fertilizer. This is a condition to avoid. 

Calcium (Ca)—This macronutrient is vital in all types of plants. It helps with the movement of carbohydrates and the growth of a healthy cell wall structure, strong stems, plant membranes, and aids in the development of the root structure.



Carbon Dioxide (CO2)—This is an odorless and colorless gas that is necessary for all plant life. It occurs naturally in the planet’s atmosphere at a percentage of 0.03. 

Chlorine—This is one of the micronutrients required by all plants. 

Chlorosis—A plant disease that results in yellowed leaves and is caused by an inadequate formation of chlorophyll. It’s usually caused by a deficiency of one of these nutrients: iron or nitrogen. It can also be caused by a pH that is out of balance. 



Clone—This is when the plant is reproduced through asexual reproduction, including cuttings, layering, and tissue culture. It is directly opposite to sexual reproduction of plants. 

Conditioning—This is when Rockwool is soaked in an acidic solution to specifically lower the pH from 8.0 to 5.5. 



Copper (Cu)—A type of element or micronutrient for plants that works as an electron carrier and internal catalyst. It plays a role in the nitrogen fixation of a plant.

Damping-Off Fungus—This is a type of disease that affects mostly young seedlings and cuttings. The stems rot at the base. Often overwatering is the main cause of this issue.

Dissolved Solids or Total Dissolved Solids—This is in reference to fertilizer salts and is measured in parts per million.

Drip Aeration—This is one of the hydroponic methods where air pressure is utilized from a small air pump. This is used to percolate the nutrient solution throughout the feed tubing that surrounds the plant.

Drip System—This is a type of watering system that provides great efficiency. Water is metered out of small water emitters through minute drops.

Drip System (Drip Emitter System)—A more efficient water system that needs a main hose with smaller water emitters in the hydroponics setup. The water is metered from these emitters and drips one drop at a time. 

Ebb-and-Flow (or Flood and Drain)—This is a specific type of a hydroponics system where aggregate pebbles are flooded with a nutrient solution. It is then drained again, which has the purpose of both feeding and aerating the medium and the root system. 

Foliar Feeding—The process of misting plants with a fertilizer solution which is then absorbed within the plant. 

Fungicide—This is a product that kills fungus or inhibits its growth.



Fungus—This is one of many spore-producing organisms from the major Fungi group. These are called plants that lack chlorophyll. They can include molds, rusts, mildews, smuts, mushrooms, and yeasts. There can be fungal diseases that attack your plants.

Geolite—A general term for various brands of clay aggregate medium. This is a lightweight and porous substrate that provides for excellent aeration. Also known as LECA–light expanded clay aggregate. It’s better for ebb-and-flow types of drip hydroponic systems. 

Germination—This is the process of getting the plant to germinate from seed to plant.

Harden-Off—This is the process of acclimating a plant to a harsher environment. This must be done when a seedling is moved indoors. 

Hormone—This is a chemical substance that can control the growth and development of plants. You can buy hormones that can be used to encourage the rooting of cuttings.

Hybrid—When there is offspring from two different plants of different breeds.


Hydrated Lime—This is a soluble lime that is used to raise or lower the pH of a plant.

Hygrometer—This is a tool that can be used to measure the humidity in the atmosphere.

Iron—Also known as Fe. This is one of the micronutrients that a plant requires.

Leaf Curl—This can happen from overwatering the plants, adding too much fertilizer, or not providing enough magnesium. It can also occur from fungal or insect damage, and negative tropism.



Macronutrients—The goal is to have a good balance of the three micronutrients in gardening, including NPK–Nitrogen, Phosphorus, and Potassium.

Manganese—A type of micronutrient that can activate enzymes in the fatty acid synthesis process, including the ones responsible for DNA and RNA production. 



Medium—This is a soilless material or type of substrate that supports the plant. It can release a nutrient solution in hydroponics. 

Micronutrients—These are trace elements, and they can include An, Cu, S, Fe, Mn, B, and Mb.

Molybdenum (Mo)—A type of micronutrient that’s essential for nitrate reduction and nitrogen fixation. 



Necrosis—What occurs when the plant tissue is dying. It can occur from a pest attack or from a serious nutrient deficiency.

Nitrogen—One of the essential nutrients for vegetative growth. It’s also needed to increase protein content in all plants.

NFT (Nutrient Film Technique)—This is a specific hydroponics method when the nutrient is directly fed into trays or grow tubes that have a thin film where the roots draw up. This allows the roots to have constant contact with the nutrients and the layer of air at the same time. 



Nutrients—These include the elements that plants naturally need for health and growth. They include macronutrients and micronutrients–also know as trace elements. When you purchase high-quality hydroponic nutrient formula it will contain all of the nutrients needed by most plants.

Nutrient Solution—This is a mix of both water and water-soluble nutrients that plants need for healthy growth.

Nutrients, Secondary—These are nutrients required by the plant that are not micronutrients. They can include calcium, magnesium, and sulfur.

pH—This is a scale that measures the alkaline balance of the growing medium. It is measured in a range of 1 to 14.

Perlite—A type of sand or volcanic glass that has been expanded by heat. It’s effective at holding in water and nutrients. It’s a form of mineral soil additive.

Phosphorus (P)—This is a macronutrient required by plants. It helps to stimulate the growth and blooming of roots. It can encourage seed growth and growth right up to the stage of maturity. 

Photoperiod—This is in reference to daylight time. It’s the difference between the length of daytime to dark in a 24 hour day. 

Photosynthesis—The process that plants utilize plant energy to collect carbon dioxide from the air and then convert it into chemical energy in the form of sugar or carbohydrates for the plants to burn. 

Propagate—Can include both asexual and sexual reproduction. Asexual is done by taking cuttings of the plant, while sexual is done by breeding different male and female flowers together. 

Pyrethium—A natural type of insecticide to treat plants that is made from the blossoms of chrysanthemums. 

Reservoir—This is a container within a hydroponics system that holds the nutrient solution in reserve.

Rockwool—This is a soilless growing medium that is made from woven strand-like fibers sourced from molten volcanic rock and limestone. It has been heated to over 2900 degrees F, enabling it to be formed into slabs, blocks, and cubes from where the growing medium is scraped. 

Secondary Nutrients—Nutrients that a plant needs next to the main ones called primary nutrients. Secondary nutrients include calcium and magnesium. 

Systemic—When a disease occurs within the plant tissue rather than its external cells. Can be also in reference to other materials or compounds that the plant can absorb. May involve products to fight disease, such as systemic fungicides to kill fungus growth on a plant.  

Vermiculite—A type of mica that has been expanded by heat energy. It’s used because of its excellent water-retention properties. It’s a good medium for rooting cuttings and also works well for soil health. 

Wick—The wick is suspended into the nutrient solution in a hydroponic setup. The nutrients flow up the wick and are then absorbed by the roots of the plant.

Zinc (Zn)—One of the essential elements required by plants to do chlorophyll synthesis. Similar to the purpose of copper or manganese.