Blue Horizons Calcium Hardness – 25kg Bucket

Blue Horizons Calcium Hardness – Calcium hardness (or total hardness) is the measure of how hard or soft the water is. Use these granules to increase your levels.

£43.19 inc VAT (£35.99 exc VAT)

In stock

Product reference: 3273 Category: Tag:


Blue Horizons Calcium Hardness – 25 kg Bucket
Blue Horizons Calcium Hardness – Calcium hardness (or total hardness) is the measure of how hard or soft the water is. Use these granules to increase your levels.
The level will vary depending on where your water supply comes from, for example in some parts of Scotland the water is very soft and in parts of Kent the water can be very hard. 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

Please refer to the Blue Horizons Pool Care guide for further product information in our downloads section.

MSDS - Blue Horizons Calcium Hardness

Download BH-Calcium-Hardness-Spa-Hardness-Plus-CLS24.pdf

Blue Horizons Pool Care Guide

Download Blue-Horizons-Pool-Care-Guide-CLS24.pdf

Warranty & Returns

This product is fully CE approved, but as a chemical based product returns are restricted, and the means of return have to be approved by us, prior to the item being returned due to the nature of these goods.

Should you require any further information, please email where we will respond to your request quickly.

Stock & Delivery

Delivery direct from suppliers, 3-5 working day service.

Delivery – Mainland UK
Orders placed before 2pm Monday to Friday we aim to dispatch on the same day, after 2pm will be the following working day. This does not include Bank Holidays, which are classed as non-working days. Should you require a Saturday delivery or have any other delivery enquiries, please email who will respond to your request quickly.

Try to include your mobile phone number in the checkout area so that our delivery drivers can contact you should they need any further assistance or clarification in delivering your order.

Please ensure you leave detailed information if your delivery address is hard to find or a new housing development. If you know there is a possibility of missing the delivery, you can at the checkout stage leave instructions for the delivery driver to leave without signature and place your goods with a neighbour or in a discreet place out of sight for your later retrieval.

Please note some areas including Scotland(post codes AB, FK, IV, KW, PA, PH, HS, KA, ZE, TR, DD,PH, PA, KY, AB, DD, KW, IV, HS), Isle of Wight, Isle of Man, will need extra carriage. We no longer ship to Jersey, Guernsey or Northern Ireland.


If you are unable to thoroughly check your delivery upon receipt, sign for it as UNCHECKED. If the package is damaged in any way, no matter how small, please sign for it as DAMAGED. We CANNOT CLAIM from our carriers for any damaged items that have not been signed for as UNCHECKED or DAMAGED.

If you sign for a delivery as OK, which you later find to be damaged, our carriers WILL NOT accept liability and you may be charged for the damaged items, in this case a delivery charge for replacement items WILL be made.

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