Apera GroStar GS1-P pH & ORP Pen Tester Kit – Hydroponics & Disinfection

Apera Instruments GroStar GS1-P pH & ORP Pen Tester Kit

The GroStar GS1-P is the go-to pen tester for hydroponic growers who need both pH and ORP (oxidation-reduction potential) in a single device. Monitor nutrient solution acidity and disinfection effectiveness — chlorine, hydrogen peroxide, ozone — without switching instruments. Built with a double-junction pH probe that resists fouling from nutrient-rich solutions, the GS1-P delivers professional-grade accuracy in a rugged, water-resistant pen format.

Why Choose the GS1-P?

pH + ORP + Temperature in One Device — consolidates disinfection and nutrient monitoring into a single pen tester
Double-Junction pH Probe — actively prevents reference contamination from complex nutrient solutions, extending sensor lifespan vs. standard single-junction testers
Disinfection Monitoring — ORP measurement tracks effectiveness of chlorine, H₂O₂, ozone, and other sanitizers in recirculating systems
Rugged, Water-Resistant Housing — built for the high-humidity environments of grow rooms, greenhouses, and grow tents
Complete Ready-to-Use Kit — arrives with calibration solutions and carrying case; no additional accessories needed
Optimal Storage at 15–25°C — standard room temperature storage for long probe life

Ideal Applications

Hydroponics: nutrient solution pH and sanitizer ORP monitoring
Aquaponics: water quality and disinfection tracking
Greenhouse and indoor grow room management
Recirculating systems with chlorine, ozone, or peroxide treatment

GroStar Series Model Comparison

Model	Parameters	Best For
GS1	pH, Temperature	General hydroponic nutrient solutions
GS2	pH, Temperature (Soil Probe)	Direct soil and solid growing media testing
GS3	EC, 500ppm, 700ppm, Temperature	Nutrient salt concentration monitoring
GS4	pH, EC, 500ppm, 700ppm, Temperature	All-in-one liquid nutrient testing
GS1-P	pH, ORP, Temperature	Hydroponics + disinfection monitoring
GS4-P	pH, EC, 500/700ppm, ORP, Temperature	Complete multi-parameter + hygiene tracking

Technical Specifications

Parameter	Specification
Measured Parameters	pH, ORP, Temperature
pH Probe Design	Double-junction (nutrient fouling resistant)
Target Market	Hydroponics, Indoor Growing, Aquaponics
Format	Complete Kit (1-EA) with carrying case
Storage Conditions	15–25°C (room temperature)
Weight	1.9 lbs
Dimensions	10 × 8 × 2 inches