Hydroponics: Concept List

500 concepts organized across 15 taxonomy categories. Generated by learning-graph-generator v0.05 on 2026-05-28.

Foundation Concepts (1–25)

1. Hydroponics Definition
2. History of Hydroponics
3. William Frederick Gericke
4. Soilless Growing Systems
5. Soil vs Soilless Comparison
6. Water as Growth Medium
7. Controlled Environment Ag
8. Indoor Growing Basics
9. Plant Growth Fundamentals
10. Cell Biology Basics
11. Photosynthesis Overview
12. Cellular Respiration Overview
13. Plant Life Cycle
14. Seed Germination
15. Seedling Development
16. Vegetative Growth Stage
17. Flowering and Fruiting Stage
18. Harvest and Post-Harvest
19. Crop Rotation Planning
20. Grow Room Layout
21. Space Utilization
22. Year-Round Production
23. Food Security Context
24. Urban Agriculture Definition
25. Hydroponics vs Aquaponics

Plant Physiology (26–60)

1. Root Anatomy
2. Root Hair Cells
3. Root Zone Oxygen Requirement
4. Nutrient Uptake Mechanisms
5. Passive Diffusion
6. Active Transport
7. Osmosis and Water Potential
8. Transpiration
9. Xylem Transport
10. Phloem Transport
11. Stomata Function
12. Leaf Structure
13. Chloroplast Function
14. Photosynthesis Light Reactions
15. Calvin Cycle
16. Chlorophyll and Pigments
17. Root Exudates
18. Rhizosphere Chemistry
19. Cation Exchange at Root Surface
20. Ion Concentration Gradients
21. Root Adaptation to Hydroponics
22. Dissolved Oxygen in Root Zone
23. Root Rot Physiology
24. Plant Stress Responses
25. Ethylene as Stress Hormone
26. Nutrient Deficiency Physiology
27. Nutrient Toxicity Effects
28. Tip Burn in Lettuce
29. Blossom End Rot
30. Interveinal Chlorosis
31. Purple Stem Syndrome
32. Necrosis Patterns
33. Growth Rate Measurement
34. Biomass Accumulation
35. Fresh Weight vs Dry Weight

Nutrients and Chemistry (61–100)

1. Essential Plant Nutrients
2. Macronutrient Definition
3. Nitrogen Functions in Plants
4. Phosphorus Functions in Plants
5. Potassium Functions in Plants
6. Calcium Functions in Plants
7. Magnesium Functions in Plants
8. Sulfur Functions in Plants
9. Micronutrient Definition
10. Iron in Plant Nutrition
11. Manganese in Plant Nutrition
12. Zinc in Plant Nutrition
13. Copper in Plant Nutrition
14. Boron in Plant Nutrition
15. Molybdenum in Plant Nutrition
16. Chlorine in Plant Nutrition
17. Nickel in Plant Nutrition
18. pH Scale Definition
19. pH and Nutrient Availability
20. Mulder's Chart
21. Electrical Conductivity (EC)
22. EC as TDS Proxy
23. Parts Per Million (ppm)
24. Nutrient Solution Concentration
25. Two-Part Nutrient Systems
26. Three-Part Nutrient Systems
27. Calcium Nitrate
28. Magnesium Sulfate (Epsom Salt)
29. Potassium Nitrate
30. Potassium Phosphate
31. Chelated Iron (EDTA/DTPA)
32. pH-Up and pH-Down
33. pH Buffer Solutions
34. Water Hardness
35. Bicarbonate Buffering
36. Cation-Anion Balance
37. Nutrient Solution Mixing Order
38. Stock Solution Concentrates
39. Nutrient Solution Temperature
40. Nutrient Solution Oxygen

Hydroponic System Types (101–135)

1. Passive vs Active Systems
2. Kratky Method
3. Kratky Air Gap Principle
4. Deep Water Culture (DWC)
5. DWC Air Pump and Air Stone
6. Single-Bucket DWC
7. Multi-Bucket DWC
8. Recirculating DWC (RDWC)
9. Nutrient Film Technique (NFT)
10. NFT Channel Design
11. NFT Flow Rate
12. NFT Pump Failure Risk
13. Ebb-and-Flow System
14. Ebb-and-Flow Timer Programming
15. Flood Table Design
16. Aeroponics Definition
17. High-Pressure Aeroponics
18. Low-Pressure Aeroponics
19. Fogponics (Ultrasonic)
20. Drip Irrigation Hydroponics
21. Wick System
22. System Selection Criteria
23. Pump Selection and Sizing
24. Reservoir Design
25. Net Pots and Baskets
26. Tubing and Fittings
27. System Failure Modes
28. Redundancy in System Design
29. Root Zone Volume
30. Plant Spacing
31. System Scalability
32. Water Recirculation
33. Run-to-Waste Systems
34. Hybrid System Designs
35. System Cleaning Between Cycles

DIY and School Systems (136–160)

1. Mason Jar Kratky Setup
2. 5-Gallon Bucket DWC Build
3. Storage Tote DWC Build
4. PVC Pipe NFT Build
5. Recycled Container Builds
6. Hardware Store Materials List
7. Net Pot Sizing Guide
8. Airline Tubing and Air Stones
9. Aquarium Air Pump Selection
10. Float Valve for Auto-Refill
11. Light-Proofing Reservoir
12. DIY pH Calibration
13. DIY EC Calibration
14. Beginner Crop Selection
15. Lettuce Varieties
16. Herb Selection for Beginners
17. Microgreens Production
18. Seeding and Germination Trays
19. Seedling Transfer Timing
20. School Garden Safety Rules
21. Student Data Protocols
22. Science Fair Project Design
23. Classroom Grow System Layout
24. System Cost Tiers
25. Upgrade Pathways for Beginners

Growing Media and Crops (161–185)

1. Rockwool Properties
2. Rockwool pH Preparation
3. Expanded Clay (Hydroton)
4. Coconut Coir Properties
5. Perlite in Hydroponics
6. Vermiculite Properties
7. Pumice as Growing Media
8. Gravel and Sand Media
9. Reusable vs Single-Use Media
10. Media Sterilization Methods
11. Media Air Porosity
12. Media Water Retention
13. Crop Selection by System Type
14. Lettuce and Leafy Greens
15. Basil and Culinary Herbs
16. Tomatoes in Hydroponics
17. Cucumbers in Hydroponics
18. Strawberries in Hydroponics
19. Microgreens and Sprouts
20. Flowering Plants (Peppers)
21. Plant Density and Spacing
22. Succession Planting
23. Transplanting Techniques
24. Harvest Timing Indicators
25. Post-Harvest Handling

Lighting Science (186–215)

1. Light and Plant Growth
2. Photosynthetic Active Radiation
3. PAR Wavelength Range
4. Red Light Effects on Plants
5. Blue Light Effects on Plants
6. Far-Red Light Effects
7. PPFD: Photon Flux Density
8. Daily Light Integral (DLI)
9. DLI Calculation
10. Photoperiod Requirements
11. Long-Day vs Short-Day Plants
12. LED Grow Light Technology
13. LED Spectrum and Efficiency
14. HID Lighting (HPS and MH)
15. Fluorescent Lighting (T5/T8)
16. LED vs HID Comparison
17. Light Intensity and Canopy
18. Inverse Square Law for Light
19. Grow Light Mounting Height
20. Light Uniformity and PPFD Map
21. Heat Output From Lighting
22. Light Schedules and Photoperiod
23. Light Recipes for Crop Stages
24. Lumens vs PPFD Distinction
25. Light Efficacy µmol/J
26. Light Meter and Quantum Sensor
27. Photoperiod Control Relay
28. Light Cost Per kWh
29. Light Energy to Biomass
30. CO2 Benefit Under High Light

Environmental Control (216–245)

1. Temperature and Plant Growth
2. Air Temperature Management
3. Solution Temperature Control
4. Root Zone Temperature Optimum
5. Relative Humidity Definition
6. Humidity and Transpiration
7. High Humidity and Disease Risk
8. Low Humidity and Tip Burn
9. CO2 Concentration Effects
10. CO2 Enrichment Methods
11. Vapor Pressure Deficit (VPD)
12. VPD Calculation
13. VPD Optimal Ranges by Stage
14. HVAC Basics for Grow Rooms
15. Exhaust and Intake Fan Sizing
16. Air Circulation and Fans
17. Grow Tent Setup
18. Grow Room Insulation
19. Data Logger Basics
20. Environmental Alarm Setpoints
21. Thermostat and Humidity Ctrl
22. CO2 Controller and Regulator
23. Ballast and Lighting Controller
24. Grow Room Automation Overview
25. Heating and Cooling Trade-offs
26. Dehumidifier Selection
27. Humidifier Selection
28. Air Filtration Carbon Filter
29. Positive vs Negative Pressure
30. Fire Safety in Indoor Grows

MicroPython Programming (246–315)

1. MicroPython vs CPython
2. Raspberry Pi Pico Overview
3. Raspberry Pi Pico W (Wi-Fi)
4. ESP32 Microcontroller Overview
5. MicroPython Installation
6. Thonny IDE Setup
7. REPL (Read-Eval-Print Loop)
8. Variables and Data Types
9. Integer and Float Types
10. String Operations
11. Boolean Logic
12. None Type and Null Checks
13. Lists in MicroPython
14. Tuples in MicroPython
15. Dictionaries in MicroPython
16. If-Else Statements
17. For Loops
18. While Loops
19. Loop Control (Break/Continue)
20. Functions and def Keyword
21. Function Parameters and Returns
22. Default Parameters
23. Lambda Functions
24. Classes and Objects (OOP)
25. Inheritance in MicroPython
26. Exception Handling Try/Except
27. File I/O in MicroPython
28. Reading Files
29. Writing and Appending Files
30. CSV File Writing in MicroPython
31. JSON in MicroPython
32. I2C Protocol Basics
33. I2C in MicroPython
34. SPI Protocol Basics
35. SPI in MicroPython
36. UART Serial Communication
37. Analog-to-Digital Converter
38. ADC in MicroPython
39. Digital-to-Analog Converter
40. PWM: Pulse Width Modulation
41. PWM in MicroPython
42. GPIO Pin Modes
43. Digital Read and Write
44. Pull-Up and Pull-Down Resistors
45. Interrupts and IRQ
46. Timer and machine.Timer
47. utime Module
48. Async/Await in MicroPython
49. asyncio in MicroPython
50. Wi-Fi Connection on ESP32
51. Socket Programming
52. MQTT Protocol Basics
53. MicroPython MQTT Client
54. HTTP Requests From MicroPython
55. Memory Management in MicroPython
56. Garbage Collection
57. Watchdog Timer
58. Boot.py and Main.py Execution
59. OTA Over-the-Air Updates
60. MicroPython Libraries
61. DS18B20 Temperature Library
62. DHT11/DHT22 Library
63. SSD1306 OLED Display Library
64. Atlas Scientific pH Library
65. Atlas Scientific EC Library
66. MCP3208 ADC SPI Library
67. Relay Module Control Code
68. Peristaltic Pump Relay Logic
69. NeoPixel WS2812 Control
70. LCD 16x2 I2C Library

Sensors and Electronics (316–345)

1. pH Electrode (Glass Electrode)
2. pH Probe Calibration
3. pH Calibration Buffers
4. EC Probe Design
5. EC Probe Calibration
6. DS18B20 Temperature Probe
7. DHT11 vs DHT22 Comparison
8. CO2 NDIR Sensor Technology
9. Water Level Sensor
10. Ultrasonic Distance Sensor
11. Float Switch
12. Relay Module
13. Dosing Pump (Peristaltic)
14. Solenoid Valve
15. Flow Sensor
16. Power Supply Selection
17. Breadboard Prototyping
18. PCB Design Basics
19. Voltage Divider Circuit
20. Op-Amp Circuits
21. Sensor Noise and Filtering
22. Moving Average Filter
23. Analog Signal Conditioning
24. Sensor Drift and Recalibration
25. Wireless Sensor Node Design
26. Battery-Powered Sensor Nodes
27. Sensor Data Timestamping
28. Multiplexed Sensor Reading
29. Atlas Scientific EZO Circuits
30. Sensor Enclosure Waterproofing

Data Analysis (346–390)

1. Data Collection Strategy
2. Sensor Reading Frequency
3. CSV File Format and Structure
4. Data Logging to SD Card
5. Cloud Data Storage Options
6. Google Sheets as Data Logger
7. Python Environment Setup
8. Jupyter Notebook Basics
9. pandas Library Introduction
10. DataFrame Creation and Structure
11. Reading CSV With pandas
12. DataFrame Indexing and Slicing
13. Date-Time Parsing With pandas
14. Resampling Time-Series Data
15. Rolling Window Statistics
16. Missing Data Handling
17. Data Cleaning and Validation
18. NumPy Library Introduction
19. NumPy Arrays
20. Array Operations Broadcasting
21. Statistical Functions in NumPy
22. Mean Median Standard Deviation
23. Correlation Analysis
24. Linear Regression
25. Regression in NumPy (polyfit)
26. scikit-learn Linear Regression
27. Matplotlib Basics
28. Line Charts for Sensor Data
29. Scatter Plots
30. Histogram and Distribution
31. Subplots and Figure Layout
32. Plotly Introduction
33. Plotly Express Line Chart
34. Plotly Interactive Dashboard
35. Dash Framework (Plotly Dash)
36. Real-Time Dashboard Updates
37. Time-Series Visualization
38. Statistical Process Control
39. Control Charts (X-bar R-chart)
40. Control Limits Calculation
41. Anomaly Detection Methods
42. Z-Score Anomaly Detection
43. IQR Outlier Detection
44. Moving Average Anomaly Detection
45. Trend Detection in Sensor Data

Food Safety and Sanitation (391–415)

1. Food Safety in Controlled Envs
2. Biofilm Definition and Formation
3. Biofilm in Recirculating Systems
4. Human Pathogens in Hydroponics
5. Listeria Monocytogenes Risk
6. Salmonella in Hydroponic Lettuce
7. Shiga Toxin E Coli (STEC) Risk
8. HACCP Principles
9. Hazard Analysis in Hydroponics
10. Critical Control Points
11. Corrective Actions (HACCP)
12. Water Source Selection
13. Municipal Water Safety
14. Well Water Testing
15. Rainwater Risks for Leafy Greens
16. Bleach Sanitization Protocol
17. Hydrogen Peroxide Sanitization
18. UV Sterilization for Water
19. Ozone Treatment
20. Sanitization Schedule
21. Food-Grade Materials
22. Worker Hygiene Protocols
23. Pest and Disease Management
24. Root Rot (Pythium) Management
25. Algae Bloom Prevention

Solar Energy and Power (416–445)

1. Solar Energy Basics
2. Photovoltaic (PV) Effect
3. Solar Cell Types
4. Solar Panel Efficiency
5. Solar Panel Watt-Peak (Wp)
6. Solar Irradiance W/m2
7. Peak Sun Hours
8. Solar Panel Output Calculation
9. Solar Panel Cost Trends
10. Levelized Cost of Energy (LCOE)
11. MPPT Max Power Point Tracking
12. Charge Controller PWM vs MPPT
13. Battery Storage Basics
14. Lead-Acid Battery
15. Lithium Iron Phosphate LiFePO4
16. Battery State of Charge
17. Battery Sizing for Grow Room
18. Inverter Selection Off-Grid
19. Grid-Tie Solar System
20. Net Metering
21. Off-Grid Solar System Design
22. Hybrid Grid and Battery System
23. Solar for Grow Lights
24. Solar for Pumps and Sensors
25. Power Monitoring With INA219
26. Energy Audit for Grow Room
27. Energy Dashboard With Plotly
28. Solar ROI Calculation
29. Carbon Footprint Indoor Growing
30. Microinverter Technology

Vertical Farming (446–470)

1. Vertical Farming Definition
2. Multi-Tier Growing Racks
3. Tower Garden Systems
4. Commercial NFT at Scale
5. Commercial DWC (Raft Culture)
6. AeroFarms Technology
7. Bowery Farming Overview
8. Gotham Greens Model
9. Container Farm Design
10. Rooftop Farm Design
11. Building-Integrated Agriculture
12. Commercial Crop Selection
13. Yield Per Square Meter
14. Light Uniformity Multi-Tier
15. HVAC for Large Facilities
16. Commercial Water Treatment
17. Automation in Commercial Farms
18. Robotic Harvesting Systems
19. AI Crop Management
20. Food Miles and Distribution
21. Proximity to Consumers
22. Cold Chain Logistics
23. Organic Certification
24. Good Agricultural Practices
25. Commercial Scale Challenges

Financial Modeling and Economics (471–500)

1. Capital Budgeting Basics
2. Net Present Value (NPV)
3. Internal Rate of Return (IRR)
4. Break-Even Analysis
5. Return on Investment (ROI)
6. Payback Period Calculation
7. Fixed vs Variable Costs
8. Operating Expense (OpEx)
9. Capital Expense (CapEx)
10. Energy Cost Modeling
11. Water Cost Modeling
12. Labor Cost Estimation
13. Nutrient Cost Per Cycle
14. Revenue Modeling
15. Wholesale vs Retail Pricing
16. Farmers Market Revenue
17. Restaurant Direct Sales
18. CSA Community Supported Ag
19. Grant Writing School Gardens
20. USDA Urban Agriculture Grants
21. Crowdfunding for Farm Startups
22. Business Plan Structure
23. Market Research Local Produce
24. Sensitivity Analysis
25. Monte Carlo Farm Risk Simulation
26. Solar Energy ROI in Hydroponics
27. Energy Projections With Solar
28. Financial Dashboard in Plotly
29. Cash Flow Forecasting
30. Scale-Up Financial Modeling