Hanna Instruments HI-38904 Pool Line Quick Total Hardness Chemical Test Kit
HI-38904 test kit comes with 30mL hardness buffer, 10mL Calmagite indicator and 50mL plastic beaker with cap. Regular testing helps to eliminate salt deposits on the walls of pools and spas.
HI-38904 Total Hardness Quick Total Hardness Control Kit
Hardness, or TH, gives the total concentration of calcium and magnesium salts on 1˚fH/0.562˚dH hardness corresponds to 10 mg/L (ppm) calcium carbonate.
The harder the water, the bigger the risk of calcium and magnesium salt deposits on the walls of the pool and spa. On the other hand, water that is too soft can be corrosive.
| Very Soft | 0-7˚fH; 0-4˚dH | |
| Soft | 7-15˚fH; 4-8˚dH | |
| Slightly Hard | 15-25˚fH; 8-14˚dH | |
| Medium Hard | 25-32˚fH; 14-18˚dH | |
| Hard | 32-42˚fH; 18-23˚dH | |
| Very Hard | Higher than 42˚fH; Higher than 23˚dH |
The ideal TH for a pool water is between 10 and 20˚fH or 5 and 11˚dH.
All required materials are included with the test kit, such as the sample beaker, indicator and buffer.
The Importance of Calcium Hardness in Pools & Hot Tubs
Calcium hardness measures the amount of dissolved calcium in your pool water with the recommended range being between 200– 400ppm.
When Calcium hardness levels are too low the water can corrode pool and plant equipment as well as attack the grout in tiled pools.
When Calcium hardness levels are too high, pool water can appear cloudy and excess calcium deposits form a rough damaging scale on pool surfaces and inside pool equipment, such as pumps and heaters.
Specifications
| Type | Titration |
| Range | 0-80 TH** |
| Smallest Increment | 1 TH** |
| Method | Calmagite |
| Ordering information | HI-38904 test kit comes with 30mL hardness buffer, 10mL Calmagite indicator and 50mL plastic beaker with cap. |
| ** | 1˚TH = 1˚fH = 0.562˚dH = 0.7˚eH = 0.2 meq/l = 10mg /l CaCO3 |
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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.