Concept Taxonomy¶
15 categories covering the multi-disciplinary scope of hydroponics: from plant biology and chemistry through embedded programming, data science, food safety, solar energy, commercial farming, and financial modeling.
Generated by learning-graph-generator v0.05 on 2026-05-28.
FOUND — Foundation Concepts¶
Concepts 1–25 | Count: 25
Entry-level concepts that establish the "why" of hydroponics. Covers the history of the field, basic plant biology, the plant life cycle, controlled-environment agriculture, and the distinction from aquaponics. No prerequisites assumed beyond high-school literacy.
PHYS — Plant Physiology¶
Concepts 26–60 | Count: 35
The biology of how plants work in a water-based growing environment: root anatomy, nutrient uptake (passive diffusion, active transport), water transport (osmosis, xylem/phloem), photosynthesis mechanics, root exudates, and visual deficiency symptoms (tip burn, chlorosis, necrosis).
NUTR — Nutrients and Chemistry¶
Concepts 61–100 | Count: 40
The chemistry layer: macronutrients (N, P, K, Ca, Mg, S) and micronutrients (Fe, Mn, Zn, Cu, B, Mo, Cl, Ni), nutrient availability vs. pH (Mulder's Chart), electrical conductivity, solution mixing from mineral salts (calcium nitrate, magnesium sulfate, potassium nitrate), bicarbonate buffering, and stock concentrate preparation.
SYST — Hydroponic System Types¶
Concepts 101–135 | Count: 35
Engineering trade-offs across all six major system architectures: Kratky (passive), DWC, NFT, Ebb-and-Flow, Aeroponics, Fogponics, plus drip and wick variants. Includes reservoir design, pump sizing, failure modes, redundancy, and cleaning protocols.
DIY — DIY and School Systems¶
Concepts 136–160 | Count: 25
Hands-on construction of low-cost systems using off-the-shelf materials. Mason jar Kratky (\(10–15), 5-gallon bucket DWC (\)50–120), PVC NFT channels. Covers beginner crop selection, school safety, student data collection protocols, and science fair project design.
GROW — Growing Media and Crops¶
Concepts 161–185 | Count: 25
Physical properties of growing media (rockwool, clay, coco coir, perlite, vermiculite) and practical crop agronomy: variety selection, transplanting, succession planting, plant density, harvest timing, and post-harvest handling.
LITE — Lighting Science¶
Concepts 186–215 | Count: 30
The physics and engineering of plant lighting: PAR, PPFD, DLI, photoperiod, LED vs. HID efficiency, light recipes for crop stages, inverse-square law, uniformity mapping, light cost per kWh, and how supplemental CO₂ interacts with high PPFD.
ENVC — Environmental Control¶
Concepts 216–245 | Count: 30
Precision management of the aerial grow environment: temperature, humidity, CO₂, VPD, HVAC sizing, fan and filtration selection, grow tent setup, data loggers, alarm setpoints, and automation controllers (thermostat, CO₂ regulator, ballast controllers).
UPYTH — MicroPython Programming¶
Concepts 246–315 | Count: 70
The largest category, reflecting the course's emphasis on embedded data collection. Covers the full MicroPython programming stack on Raspberry Pi Pico/Pico W and ESP32: language fundamentals (variables, control flow, functions, OOP, exception handling), file I/O and CSV logging, hardware interfaces (I2C, SPI, UART, ADC, PWM, GPIO, interrupts, timers), async programming, Wi-Fi, MQTT, HTTP, memory management, OTA updates, and sensor-specific libraries (DS18B20, DHT22, Atlas Scientific pH/EC, SSD1306, relay, peristaltic pump).
SENS — Sensors and Electronics¶
Concepts 316–345 | Count: 30
Hardware-level sensor selection, calibration, and signal conditioning: pH glass electrodes, EC probes, temperature (DS18B20), humidity (DHT11/22), CO₂ (NDIR), water level, flow sensors, relay modules, dosing pumps, solenoid valves, breadboard and PCB design, noise filtering, sensor drift, wireless node design, and waterproof enclosures.
DATA — Data Analysis¶
Concepts 346–390 | Count: 45
The data science pipeline from sensor to insight: CSV logging to SD card and cloud (Google Sheets), Jupyter notebooks, pandas DataFrames, time-series resampling and rolling statistics, NumPy arrays and statistics, linear regression, Matplotlib and Plotly visualization, Plotly Dash real-time dashboards, Statistical Process Control (SPC) with control charts, and anomaly detection (Z-score, IQR, moving average).
SAFE — Food Safety and Sanitation¶
Concepts 391–415 | Count: 25
Critical non-obvious content for food crops: biofilm formation and pathogen spread in recirculating systems, HACCP principles adapted to controlled-environment agriculture, specific pathogens (Listeria, Salmonella, STEC), water source selection, sanitization protocols (bleach, H₂O₂, UV, ozone), pest and disease management (Pythium root rot, algae blooms, fungus gnats, aphids).
SOLAR — Solar Energy and Power¶
Concepts 416–445 | Count: 30
Declining-cost solar energy as the power source for grow operations: PV effect, solar cell types, MPPT charge controllers, battery storage (lead-acid vs. LiFePO₄), off-grid and grid-tie system design, net metering, energy audits for grow rooms, power monitoring (INA219), Plotly energy dashboards, solar ROI calculation, and carbon footprint analysis.
VERT — Vertical Farming and Commercial Scale¶
Concepts 446–470 | Count: 25
The commercial endpoint: multi-tier rack systems, tower gardens, container farms, rooftop farms, commercial NFT and DWC at scale, profiles of AeroFarms/Bowery/Gotham Greens, HVAC for large facilities, robotic harvesting, AI crop management, food miles, cold chain logistics, organic certification, GAP, and the economic challenges of scaling.
FIN — Financial Modeling and Economics¶
Concepts 471–500 | Count: 30
Quantitative business skills for operating a hydroponics enterprise: NPV, IRR, break-even, ROI, payback period, OpEx/CapEx decomposition, energy and water cost modeling, revenue modeling (yield × price), market channels (farmers market, restaurant direct, CSA), grant writing (USDA urban ag grants), sensitivity analysis, Monte Carlo simulation, declining-solar energy projections, and Plotly financial dashboards.