Hydroponics is a soilless cultivation method where plants grow in a nutrient-rich water solution, with their roots either submerged or intermittently exposed to the solution. Unlike traditional farming, hydroponics delivers nutrients directly to the roots, maximizing growth efficiency.

Hydroponic Environmental Monitoring Sensors

Precise control of water chemistry and ambient conditions is critical. Key sensors include:

(1) Nutrient Solution Monitoring

Sensor	Purpose	Target Range
EC Sensor	Measures nutrient concentration (electrical conductivity).	1.0–3.0 mS/cm (crop-dependent).
pH Sensor	Maintains optimal acidity for nutrient uptake (e.g., lettuce: pH 5.5–6.5).	±0.1 accuracy.
Dissolved Oxygen (DO)	Ensures root oxygenation; prevents rot (DO >5 mg/L).	Optical/electrochemical.
Water Temperature	Affects root health and oxygen solubility (ideal: 18–22°C).	±0.5°C accuracy.

(2) Ambient Environment Monitoring

Sensor	Purpose
Air Temp/Humidity	Prevents condensation (humidity 50–70%) and heat stress.
CO₂ Sensor	Optimizes photosynthesis (800–1200 ppm for fast growth).
PAR Sensor	Measures photosynthetically active radiation (e.g., leafy greens: 200–400 μmol/m²/s).

Small-Scale Hydroponic Sensor Setup (NFT System for Lettuce)

System Specifications:

Type: Nutrient Film Technique (NFT) with 12 lettuce plants.

Area: 2 m² indoor grow tent with LED lighting.

Automation: Cloud-based monitoring + automated pH/EC adjustment.

Recommended Sensors:

Sensor	Model Example	Qty	Notes
EC/pH Combo Sensor	BGT-WMPS(O1)	1	Submerged in nutrient reservoir.
DO Sensor	BGT-WDO(K)	1	Calibrate weekly.
Water Temp Sensor	BGT-WMPS(O1)	1	Attached to reservoir wall.
Air Temp/Humidity	BGT-WSD2	1	Mounted at canopy height.
CO₂ Sensor	BGT-WSD2	1	For enclosed spaces.
PAR Sensor	BGT-PAR1	1	Positioned near leaves.