Glossary: Water Engineering and Hydroponics Terms

• Advanced Oxidation Process (AOP): is a chemical treatment process designed to remove organic (and sometimes inorganic) materials in water by oxidation through reactions with hydroxyl radicals
• Aeroponics: A soilless/hydroponic cultivation method where the plant’s roots are suspended, and the rhizome is exposed to a dark, humid environment regularly saturated with a spray or mist. High dissolved oxygen levels combined with a nutrient-rich mist promote rapid growth and efficient nutrient absorption.
• ASTM (American Society for Testing and Materials) is a global organization that develops standards for various industries, including construction, manufacturing, environmental science, materials testing, and consumer products.
• AWWA (American Water Works Association) is a nonprofit, professional organization dedicated to managing and improving water supply and quality. Founded in 1881, it is one of the oldest and largest organizations focused on water-related issues, including potable water, wastewater, stormwater, and water reuse.
• Backflow Preventer is a plumbing device meant to stop potentially contaminated or water from flowing backward into the supplied clean water.
• Bypass is an alternative route or pipe that diverts flow around a fluid system element, such as a valve, filter, or instrument. It allows water to continue flowing even if the main system is shut off for maintenance, repair, or replacement.
• Chemigation is applying chemicals, such as fertilizers, pesticides, herbicides, fungicides, or soil amendments, to crops through a water system.
• Condensate: liquid formed by condensation of vapor. An air-conditioning unit condenses water vapor in the cooling process in the same manner as a cold can set out in a warmer climate.
• Condensate Drain (CD): Liquid collected from HVAC equipment whereby water vapor is extracted via condensation, typically on the cooling (evaporative) coil.
• Deadband: A neutral zone of input values assigned to prevent the control device from activating equipment in rapid succession.
• Deep Water Culture (DWC): A hydroponic technique where plant roots are submerged in oxygenated and temperature-controlled nutrient-rich water.
• Dissolved Oxygen (DO): The amount of oxygen in water, measured in milligrams per liter (mg/L) or as a saturation percentage. Dissolved oxygen is a critical indicator of water quality, as it supports aquatic life and affects biological and chemical processes. Factors such as temperature, salinity, and pressure influence oxygen solubility in water. Proper dissolved oxygen levels are essential for maintaining healthy ecosystems in hydroponics, aquaculture, and water treatment systems.
• Drip Irrigation System: An irrigation method that delivers water and nutrients directly to the plant roots through a network of pipes, valves, hoses, and emitters. This irrigation method ensures precise nutrient delivery and is an effective tool to reduce water waste.
• Ebb and Flow System: A hydroponic system that periodically floods a plant’s rhizome (root zone) with nutrient solution and then gradually drains it back, allowing the plants to receive water and nutrients in programmed cycles.
• Emitters are components in drip or micro-irrigation systems that deliver water directly and evenly to the root zones of an array of plants. These small, specialized outlets provide precise, controlled water flow, ensuring efficient irrigation and promoting healthy plant growth.
• Evapotranspiration (ET): saturated water converted to water vapor in the climate via two primary pathways: evaporation from soil and other surfaces and transpiration from plants. In irrigation and plant biology, ET is a critical factor in determining water requirements, as it quantifies the total water lost and helps optimize irrigation strategies for efficient water use.
• Fertigation is the process of delivering fertilizers, nutrients, and sometimes soil amendments directly to plants through an irrigation system.
• Field Capacity (FC): refers to a maximum saturation capacity that a growing medium can retain after excess water has drained away.
• High-density polyethylene (HDPE) is a durable, versatile thermoplastic commonly used in plumbing and piping systems. It is prized for its strength, flexibility, and chemical resistance, making it ideal for various water distribution, drainage, and irrigation applications.
• Hydroponic Grow System Planning: The process of developing comprehensive strategies and usage rates to optimize water processes in large-scale hydroponic operations.
• Hydroponic System Design and Drafting: Creating detailed technical drawings and plans to construct efficient and effective hydroponic water systems tailored to specific operational needs.
• Hydroponic System Maintenance: Regular servicing of water systems to prevent malfunctions, extend lifespan, and maintain optimal water quality in hydroponic setups.
• Hydroponic Water System Installation: The implementation of designed water systems and solutions to ensure they are effective, maintainable, and meet the operational requirements of hydroponic facilities.
• Inner Diameter (ID): refers to the measurement of the internal width of a circular object, such as a pipe, hose, or tube. It is the distance across the object’s interior, measured from one inner wall directly to the opposite inner wall, passing through the center.
• Impeller: The impeller is the central component of an agricultural pump. It is a rotating component typically made of metal vanes. Its unique shape imparts energy to the fluid through flow and pressure as it flows through the pump cavity.
• International Plumbing Code (IPC): is a model code that provides regulations for the design, installation, and inspection of plumbing systems to ensure public health, safety, and welfare. It is published by the International Code Council (ICC) and is widely adopted in the US as the basis for local plumbing codes.
• Irrigation supplies water to plants, crops, or landscapes through artificial means to support their growth and development. Irrigation takes many forms, including drip, sprinkle, spray, and misting.
• Low-Density Polyethylene (LDPE): is a thermoplastic polymer known for its flexibility, durability, affordability, and resistance to moisture and chemicals. LDPE is one of the most widely used plastics, particularly in lightweight and flexible applications.
• Leachate: is the runoff solution from the base of the growing media after irrigation
• Leaching Fraction (LF): is the volumetric ratio of the leachate vs. the total irrigation event LF (%) Leachate volume (ml) / Total irrigation volume (ml) x 100
• Mainline pipe: is a primary pipeline that serves as the “main” distribution line for a fluid or gas. Mainline pipes are used in various applications, such as water systems, natural gas networks, or industrial processes.
• Mass Based Water Content (MBWC): is the ratio of the mass of water within a material to the dry mass of that material. It is a key measure used in soil science and agriculture to quantify moisture levels.
• Microclimate: localized environmental conditions created and managed within a controlled growing area, such as a greenhouse, vertical farm, or growth chamber. These conditions differ from the broader climate outside the structure and are carefully optimized for plant growth.
• Microcontroller (MCU): an integrated circuit designed to perform a specific task within an embedded system. A microcontroller typically includes a processor, memory, and input/output peripherals on a single chip, enabling it to control devices such as pumps, sensors, and displays in applications like water management and automation.
• Net Positive Suction Head (NPSH): is the available absolute pressure at the suction of a system pump.
• Net Positive Suction Head Available (NPSHA) measures the absolute pressure available at the suction side of a pump.
• Net Positive Suction Head Required (NPSHR) is the minimum absolute pressure required at the suction side of a pump to prevent cavitation.
• Non-potable Water is not suitable for human consumption but can be used for specific agricultural purposes, such as irrigation. Although it does not meet the quality standards set for drinking water, it may still be acceptable for supporting plant growth.
• Outer Diameter (OD): is the total diameter of a cylindrical component measured across its external surface. It is the distance from one outer edge of the object, through its center, to the opposite outer edge.
• Oxygen Reduction Potential (ORP): is a measure of a solution’s ability to either release or accept electrons during chemical reactions. ORP is a key indicator of a solution’s oxidative or reductive strength, typically measured in millivolts (mV).
• Oxygen Enrichment, AKA “Nanobubbles”: Enhancing the oxygen levels in the root zone or nutrient solution to promote healthier plant growth and improve nutrient uptake.
• Pot Capacity: A fully saturated state of a pot of growing media at its highest water content (WC) point, and any incremental irrigation will cause runoff or leachate.
• Potential of Hydrogen (pH): a scale from 0 to 14 is used to gauge the acidity or basicity of an aqueous solution.
• Polyethylene (PE) is a versatile plastic material widely used in various agricultural applications due to its durability, flexibility, chemical resistance, and affordability.
• Polyvinyl Chloride (PVC): is a widely used thermoplastic material in agriculture due to its durability, versatility, and cost-effectiveness. In agriculture, PVC is used mainly for irrigation, drainage, and other water management applications.
• Potable Water: is water that is safe for human consumption. It is free from harmful contaminants such as bacteria, viruses, chemicals, and other pollutants that could cause illness or adverse health effects.
• Permanent Wilting Point (PWP): is the minimum soil moisture level at which a plant can no longer extract water from the soil, resulting in irreversible wilting. At this point, even if the plant is rehydrated, it cannot recover its turgidity. It is typically expressed as a percentage of soil moisture by weight or volume and varies depending on soil texture and composition.
• Process Flow Diagram (PFD): A schematic representation outlining the flow of water and nutrients in a hydroponic system, aiding in planning and optimization.
• Process & Instrumentation Diagram (P&ID) is a detailed diagram showing the piping and related components of a physical process flow, including instrumentation and control devices.
• Programmable Logic Controller (PLC) is an industrial-grade computer specifically designed to monitor inputs, process data based on pre-programmed logic, and control outputs to automate a water process or system.
• Reduced Pressure Assembly (RPA) is an entire backflow prevention assembly, including the valves, pressure zones, and relief valve components.
• Root Hairs, or “trichoblasts”, are microscopic extensions of individual root cells, typically found in the zone of maturation near the tips of plant roots. These hair-like structures increase the root’s surface area, enhancing the plant’s ability to absorb water and nutrients from the soil. Root hairs are critical in nutrient exchange and essential for healthy plant growth.
• Stock Tank (Concentrated solution): A container where concentrated fertilizers or additives are prepared and stored before mixing.
• Stomata are small openings or pores found on the surface of leaves and stems in plants. Stomata facilitate gas exchange by allowing carbon dioxide to enter for photosynthesis and oxygen to exit as a byproduct. They also play a critical role in regulating water loss through transpiration.
• Testing and Commissioning: The process of verifying that water systems are functioning as intended and meeting defined performance requirements before full-scale operation.
• Variable-frequency drive (VFD): An electronic device that controls the speed and torque of electric motors by varying the frequency and voltage of its power supply. VFDs are commonly used in water management applications to enhance energy efficiency, improve process control, and extend equipment lifespans.
• Water Content (WC): is the proportion of water present in a material or substance, expressed as a percentage of its total mass or volume.
• Water Engineer: A water engineer specializes in the planning, designing, and managing water-related infrastructure and systems. They are responsible for addressing various aspects of water management, including water supply, treatment, distribution, wastewater management, and stormwater control.
• Water Reclamation System: Systems designed to capture and reuse waste or runoff water in hydroponic operations, significantly reducing water-related expenses and conserving resources.
• Water Testing and Analysis: Assessing water quality by identifying sources of contamination and determining necessary improvements to ensure safe and effective water use in hydroponic systems.
• Vapor Pressure (VP): The singular or partial pressure exerted by a vapor (i.e., water) that exists in a gaseous mix (i.e., air).
• Volumetric Water Content (VWC): measures the amount of water held in a given volume of a growing medium, such as hydroponic substrate or soil. It is expressed as a percentage and is calculated by dividing the water volume by the substrate’s total volume. In hydroponics, WC is crucial for monitoring and managing the water available to plant roots, ensuring optimal moisture levels for plant growth. Maintaining the right WC can improve nutrient absorption, prevent overwatering, and enhance oxygen availability in the root zone.