











Hanna Instruments-98118 GroLine Waterproof Hydroponic pH & Temperature Tester
The Hanna Instruments-98118 pH/temperature tester is our latest pocket meter for measuring the pH of a hydroponic nutrient solution. The ergonomic design allows this tester to fit comfortably in your hand. The large easy to read LCD display shows both pH and temperature along with calibration, stability and low battery indicators. All operations are simplified to two buttons. One is for turning the meter on/off and the other for automatic one or two point calibration.
This GroLine pocket pH Tester is an affordable way to measure the pH of hydroponic nutrient solutions. The maintaining of an optimal pH is essential to maximise optimum growth. The general rule of thumb is that as pH increases the solubility of minerals and nutrients decrease. It is important that nutrients are soluble for plants to uptake and use for growth. The pH of nutrient solution can also affect the bacteria that fix nitrogen for the plant to use. Every plant has optimum pH levels for growth. Below is a table for the ideal pH range for a variety of plants.
The Hanna Instruments-98118 can be used to measure the pH in soils as well as nutrient solutions. To measure the pH of soil as a slurry it is recommended to use a mixture of 1 part soil to 1 part water. The slurry is allowed to rest for 10 minutes so that the solids will settle out and the pH of liquid above can be measured.
The Hanna Instruments-98118 is an advanced meter while maintaining simplicity. The front of the meter has two buttons. One is for turning the meter on and off while the other is used to enter the calibration mode. There is a third button in the battery compartment that allows the user to customise the meter to their preference. Customisation includes temperature readout in °C or °F, automatic shut off selectable from 8 minutes, 60 minutes or disabled, and lastly the choice of using Hanna's Quick Cal pH/EC standard or traditional buffers values of pH 4.01, 7.01 and 10.01.
The electrode features a unique extractable cloth junction. The reference junction of a pH electrode, also known as a salt bridge, provides an electrical pathway between the internal reference cell and the sample. Any clogging of the junction will result in a disruption of the electrical pathway. When this happens the readings will be erratic and take a very long time to stabilise. With the Hanna extractable junction a small portion of 1/8" is extracted or pulled to expose a clean surface. With the junction renewed the clogging is cleared allowing the meter to still be used. The overall length of the junction is about 1" so the junction should only be extracted periodically.
Key Features
- Built in temperature sensor for Automatic Temperature Compensated measurements
- Renewable junction to clear any clogging that causes readings to drift and be erratic
- Stability indicator that disappears once a stable reading is obtained
- Automatic calibration to one or two points at a push of a button
- Uses Hanna's Quick Cal pH/EC standard with a pH value of 6.86
- Battery % level displayed at start up
- Low battery indicator that is displayed when less than 10% battery life is remaining
Frequently Asked Questions
Clear answers to help you choose the right water testing solution with confidence
Which brands of water testing kits do you supply?
Do you provide kits for both home and professional use?
Yes — whether you’re a pool or spa owner, aquarium keeper, utility company, or a university laboratory, we have the right solution for your needs.
Can I arrange servicing or calibration for my photometer?
Absolutely. We also provide servicing and calibration to keep your photometers accurate and reliable.
How quickly do you dispatch orders?
Orders placed before 2:30 pm (Monday–Friday) are dispatched the same day. We also ship on Saturdays for your convenience.
Which couriers do you use for delivery?
We deliver through UPS, DPD, and Royal Mail. You can also choose to upgrade to next-day delivery at checkout.
What is your return policy?
We accept returns within 14 days of delivery provided the items are unused, in their original packaging, and in resalable condition. Please contact our team before returning any items.
Can I place bulk or business orders?
Yes, we welcome bulk, trade, and institutional orders. For tailored pricing or large quantities, please get in touch with us directly.
How can I get help if I’m unsure which kit to buy?
You can call us at 📞 +44 (0)115888 2726 and our team will guide you in choosing the most suitable kit for your needs.