# Hydroponics > Part of: [Irrigation](/irrigation.md) · Provider: [DutchGreenhouses](/) Hydroponics is cultivation without soil, in which the root environment is supplied entirely through the nutrient solution. The term describes the absence of soil rather than a watering technique, so it covers stone wool, water culture and aeroponics alike, and separates them from media such as coir that still buffer nutrients. ## Facts | Property | Value | |---|---| | Root oxygen demand | 200 mg O₂/m² per hour | | Oxygen delivered by saturated drip water | 9 mg O₂/m² per hour | | Stone wool water content working window | 55–75 % | | Oxygen shortfall causing root death | 20–30 % of demand | | Growth inhibition measured in untreated drain water | 20 % | Irrigation # Hydroponics. Take away the soil and you control everything the root sees. ## Take away the soil and you control everything the root sees Hydroponics is the foundation of modern high-tech horticulture: growing without soil, so that the root zone stops being an uncontrolled variable and becomes a managed environment. Instead of soil with its unpredictable structure, nutrition and pathogens, the crop grows in an inert substrate or directly in a water system, fed a precisely dosed nutrient solution. Take the soil away and the grower controls everything the root sees — exactly how much water, exactly which nutrients, exactly how much oxygen — and that control is what unlocks the yields, quality and resource efficiency that define commercial greenhouse growing. There are two broad families. Substrate systems grow the crop in slabs or bags of an inert medium such as stone wool, coir or perlite, which holds the roots and buffers water and nutrients while drippers deliver the fertigation recipe — the standard for vine crops like tomatoes, peppers and cucumbers. Pure water systems dispense with substrate altogether: in NFT (nutrient film technique) a thin film of solution flows continuously past the roots, while in deep water culture the plants float with their roots suspended in an aerated nutrient pond. Leafy greens and herbs thrive on these. The right choice depends on the crop, the layout and the operation’s risk profile. The benefits are consistent across both. Precise root-zone control means the crop is never over- or under-watered and receives an exact nutritional recipe that shifts with its growth stage. Eliminating soil eliminates soil-borne diseases and weeds, cutting crop-protection needs. And because hydroponic systems are almost always run as closed, recirculating loops, drain water and nutrients are captured and reused, so water and fertiliser consumption fall dramatically compared with open-field growing. This is the engine behind the yields of our Expert and Plus Series greenhouses and the standard for commercial vegetable production worldwide. DutchGreenhouses® designs the hydroponic system — substrate or water, irrigation, dosing and recirculation — around the crop and water source so the root zone performs as engineered. Get in touch to design a hydroponic system for your project. From the knowledge base ## Reads you might find interesting ceacultivationbusiness-case ### Grow Like a Pro: Starting Smart, Growing Strong How Grow Like a Pro combines smart farming, CEA technology and local partnerships for eco-friendly, profitable, pesticide-free greenhouse pr Read article education ### The Case for a College Greenhouse Why a college greenhouse belongs in the curriculum: teaching science, craftsmanship, business logic and sustainability, and preparing studen Read article education ### The Case for a High School Greenhouse Why every high school greenhouse matters: how it makes STEM tangible, builds responsibility and teamwork, and helps students discover their Read article education ### Greenhouses in Education: The Case for Schools Greenhouses in education reconnect students to reality — the full case for why every school, high school, college and trade program should h Read article historyconstruction ### The Origins of Greenhouse Horticulture: My Backyard A tour through greenhouse horticulture history: from 19th-century Westland fruit walls to the “City of Glass” and today’s international high Read article company ### DutchGreenhouses Rebranded: A New Corporate Identity Announcing our new corporate identity — a visual style reflecting our dedication to advanced, high-quality greenhouse projects and The Futur Read article ## FAQ **What does hydroponic actually mean?** It denotes the absence of soil, not a way of giving water. Drip irrigation, ebb and flow, nutrient film and aeroponics are delivery methods that appear in both soil-grown and soilless systems. The useful physical variable is cation exchange capacity: an inert medium buffers nothing, so the solution is the entire root environment. **Is coco coir hydroponic?** It is sold as hydroponic and behaves in between. Stone wool, perlite and water culture are chemically inert, so what is dosed is what the root receives. Coir carries real cation exchange capacity and buffers nutrients, which changes how a recipe behaves. Treating the two as one category is where nutrition plans go wrong. **Should the nutrient solution be aerated?** Not for drip-on-slab, on a mass balance. Roots demand at least 200 milligrams of oxygen per square metre per hour and oxygen-saturated drip water at one litre per square metre delivers nine. Aeration does matter where saturated solution flows past roots continuously, as in nutrient film technique. The controlling variable on slabs is substrate air content. **Does recirculated water build up growth-inhibiting root exudates?** Wageningen tested this and found a bacterial cause instead. Untreated drain from a rose trial scored 80 percent of reference in a bioassay, and heat, ozone and ultraviolet each removed most of the effect while bacterial counts collapsed. Crop-protection products at practice concentrations inhibited nothing. The inhibition is real; standard disinfection already addresses it. ## Related [Irrigation](/irrigation.md) · [Dosing](/irrigation/dosing.md) · [Post-Treatment](/irrigation/post-treatment.md) · [Substrate](/glossary/substrate.md) · [Stone Wool Slab](/glossary/rockwool.md) · [Cultivation Gutter](/glossary/cultivation-gutter.md) · [Drip Irrigation](/glossary/drip-irrigation.md) ## See also https://www.wikidata.org/wiki/Q191667 · https://en.wikipedia.org/wiki/Hydroponics · https://aims.fao.org/aos/agrovoc/c_3734