Hanna Instruments-93735-01 Total Hardness Medium Range Colorimetric Reagents, 100 tests
Pre-made reagents for ease of use
Prepared with high purity chemicals
Reagents for hardness, total, Colorimetric method
The Hanna Instruments-93735-01 are high quality reagents that are pre-measured, allowing for users to achieve fast and accurate colorimetric measurements. These reagents follow an adaptation of the EPA recommended method 130.1 in which the reaction between calcium, magnesium, and the reagents causes a red-violet tint in the sample. By simply adding liquid reagent A, two drops of reagent B, and the packet of reagent C to the sample, the reaction between calcium and magnesium and the reagents causes a colour change dependent upon concentration. The intensity of colour is determined by the compatible Hanna Instruments-96735 photometer and the concentration will be displayed. The results will be displayed in mg/L (ppm) as CaCO3. These reagents are designed to be used with samples that have an expected range of 200 to 500 mg/L (ppm) CaCO3total hardness.
Tip for an accurate measurement
It is important that the sample does not contain any debris.
When the cuvette is placed into the measurement cell, it must be dry outside and completely free of fingerprints, oil or dirt. Wipe it thoroughly with Hanna Instruments-731318 or a lint-free cloth prior to insertion.
Shaking the cuvette can generate bubbles, causing higher readings. To obtain accurate measurements, remove such bubbles by swirling or by gently tapping the cuvette.
Do not let the reacted sample stand for too long after reagent is added, or accuracy will be lost.
After the reading, it is important to discard the sample immediately, otherwise the glass might become permanently stained.
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.