Glossary

Use this glossary of common hydroponic terms and get up to speed.

  • An acidic solution has a ph below 7.

  • Supplying soil and roots with air or oxygen. Geolite is an example of a medium with excellent aeration. In some hydroponic systems, a nutrient solution is aerated by the output of an aquarium pump.

  • A system in which the roots of a plant are consistently or intermittently misted with fine droplets of nutrient solution.

  • Any ph over 7 is considered alkaline.

  • Fertilizer high in phosphorus (P) that increases flower yield.

  • The function of this micronutrient is not well understood, but it is suspected that it might aid carbohydrate transport.

  • Leaf tips that turn dark from excess fertilizer and salt burn.

  • Calcium is vital in all parts of plants to promote the translocation of carbohydrates, healthy cell wall structure, strong stems, membrane maintenance and root structure development. Calcium is a macronutrient.

  • A colorless, odorless, tasteless gas in the air necessary for plant life. Occurs naturally in the atmosphere at .03%.

  • This micronutrient is essential for photosynthesis, where it acts as an enzyme activator during the production of oxygen from water.

  • The condition of a sick plant with yellowing leaves due to inadequate formation of chlorophyll. Chlorosis is caused by a nutrient deficiency, usually iron or nitrogen; nutrient deficiencies are themselves often caused by a ph that is out of the acceptable range.

  • A plant produced through asexual reproduction including, but not limited to, cuttings, layering and tissue culture.

  • To soak new Rockwool in an acidic solution to lower the ph from 8.0 to 5.5.

  • This micronutrient is an internal catalyst and acts as an electron carrier; it is also believed to play a role in nitrogen fixation.

  • Disease that attacks young seedlings and cuttings, causing stems to rot at the base; overwatering is the main cause of damping-off.

  • The amount of dissolved solids, usually fertilizer salts, that are measured in water in parts per million.

  • A hydroponic method wherein air pressure from a small air pump is used to percolate nutrient solution out through a ring of feeder tubing which encircles the plant.

  • A very efficient watering system that employs a main hose with small water emitters. Water is metered out of the emitters, one drop at a time.

  • A hydroponic system in which the medium, usually aggregate pebbles, is periodically flooded with nutrient solution and then drained again, feeding and aerating the medium and root system.

  • Misting plants with fertilizer solution, which is absorbed by the foliage.

  • A product that destroys or inhibits fungus.

  • Any of a major group (Fungi) of saprophytic and parasitic spore-producing organisms usually classified as plants that lack chlorophyll and include molds, rusts, mildews, smuts, mushrooms, and yeasts. Common fungal diseases that attack plants are “damping-off,” Botrytis, and powdery mildew.

  • The process of causing the initiation and development of a plant from seed.

  • To gradually acclimatize a plant to a more harsh environment. A seedling must be hardened-off before planting outdoors.