Test All Water Calcium Hardness Plus - Calcium Chloride
This is used to increase the levels of Calcuim Hardness in Spa and Hot Tub water. The ideal level for your spa and hot tub water needs to be between 100ppm and 200ppm, and for swimming pools, the ideal level is 200ppm. Having low Calcium Hardness (very soft water) can cause the water to become corrosive which can result in staining, etching or distoring of different types of spa and hot tub surfaces.
For 1000 litres 15g will increase by 10mg/l or 38g will increase by 25g/l
For 1500 litres 23g will increase by 10mg/l or 56g will increase by 25g/l
The level will vary depending on where your water supply comes from. The hardness depends upon the amount of mineral salts (mainly calcium) that are dissolved in the water and the more salts there are the harder the water is.
If the calcium hardness of your pool water is less than 200mg/l then it should be increased using Blue Horizons Calcium Hardness Raiser, details of dose rates can be found below:
| Calcium Hardness Dosing Rates | |||||||
| Pool Volume | To Increase Calcium Hardness by: | ||||||
| Litres | Gallons | 10 mg/l | 25 mg/l | 50 mg/l | |||
| 4,545 | 1,000 | 68g | 170g | 340g | |||
| 11,364 | 2,500 | 170g | 425g | 850g | |||
| 22,727 | 5,000 | 340g | 850g | 1.7kg | |||
| 45,455 | 10,000 | 680g | 1.7kg | 3.4kg | |||
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.