Hanna Instruments HI-3812 Hardness (Total) test kit
Hardness in water is mainly due to the presence of Calcium and Magnesium ions and each one contributes to the amount of total hardness.
Titration is used to find the concentration of an identified chemical in a solution (e.g., water).
In our standard Titration kits, there will be a Titrant solution that is added to the solution (e.g., water) to be tested to make it change colour. The Reagent is then added under monitored conditions.
Water Hardness Test Kit
The HI-3812 test kit tests the hardness level as mg/L (ppm) calcium carbonate, via an EDTA (ethylene-diamine-tetraacetic acid) titration. Range (0.0-30.0 mg/L) (0-300 mg/L).
During testing, when colour change is achieved, under careful conditions - usually using a burette – the reagent is added, drop by drop, until the solution turns to the colour required. The user will then count how many drops of reagent were used to achieve complete colour change. The number of drops used will determine the chemical concentration and results can be found in the manual included.
Water hardness has traditionally been defined as the capacity of water to precipitate soap. The ionic species in the water causing the precipitation was later found to be primarily calcium and magnesium. In the present, therefore, water hardness is actually a quantitative measure of these ions in the water sample. It is also now known that certain other ion species, such as iron, zinc and manganese, contribute to the overall water hardness. The measure and subsequent control of water hardness is essential to prevent scaling and clogging in water pipes.
Order information
The HI-3812 test kit is supplied with the following:
- 30 mL hardness buffer
- 10 mL calmagite indicator
- 120 mL EDTA solution
- 20 mL plastic beaker with cap and 50 mL plastic beaker with cap
- 1 mL syringe with tip
Specifications
| Method | Titration |
| Range | 0.0-30.0 mg/L 0-300 mg/L |
| Smallest Increment | 0.3 mg/L 3 mg/L |
| Chemical Method | EDTA |
| Number of Tests | 100 |
| Weight | 460 g |
Downloads
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.