Hanna Instruments 98509 / HI98509 | Checktemp® 1 Digital Thermometer | Freshwater, Saltwater & Aquaculture

Get fast, accurate water temperature readings with the Hanna Instruments HI98509 Checktemp® 1 Digital Thermometer. Built for aquariums, ponds, and aquaculture systems, this reliable thermometer provides precise readings for both freshwater and saltwater environments. The stainless steel probe easily measures water, substrate, or air temperature — helping you maintain stable, healthy conditions for fish, coral, and plants.

• Accurate ±0.2°C readings within -30 to 120°C range
• Measures -50.0 to 150.0°C (-58.0 to 302°F)
• NTC thermistor sensor delivers fast, stable results
• 1 m (3.3 ft) flexible silicone cable for easy probe placement
• Selectable °C/°F display
• Automatic CAL Check™ verifies calibration at startup
• Large LCD screen with clear readout
• IP65 water-resistant housing
• Auto shut-off (8 min, 60 min, or off)
• Durable stainless steel probe ideal for aquarium and pond use

Water Type Compatibility

• ✅ Freshwater systems
• ✅ Saltwater and reef aquariums
• ✅ Brackish and aquaculture setups
• ✅ Terrarium and ambient air readings

Recommended For: Reef tanks, planted aquariums, sumps, breeding tanks, aquaculture ponds, and temperature calibration for heaters or chillers.

More Information

Cross-Compatible Tools:

• Pair with aquarium testing kits and controllers for complete system monitoring.
• Use with filtration and sump equipment to verify temperature balance.
• Great companion for water conditioners and additives used during temperature-sensitive dosing.