Getting down to the bone about calcium hardness levels - hot tub.

Getting down to the bone about calcium hardness levels – hot tub.

Throughout the UK, the range of water hardness varies according to the geographical area within which you live. Water naturally has a level of hardness which is defined by the amount of minerals dissolved within – of which calcium is one. 

To help with the water management control in your hot tub, spa or pool water, you can find out (from your local water suppliers’ website) if your water source is hard or soft.

It will probably come as no surprise that your hot tub has an optimal calcium hardness range to help achieve peak performance of your spa. The ideal total hardness range if you have an acrylic finish is 100 – 250ppm or 250 – 450ppm if you have a plastic finish, anything above or below these optimal ranges will need your attention. 

It is worth noting, that a calcium hardness reading of above 1,000ppm is (for the purpose of the operation of your hot tub) is to be considered and treated as extremely high.

How does Calcium affect my hot tub?

Depending on if you have high or low levels of calcium in your hot tub or spa, you can experience:

Corrosion – of fittings and parts associated with low levels of calcium.

Slimy – if your water feels slimy, this could be due to low calcium levels.

Limescale – high calcium levels and imbalanced pH can result in limescale build up. This can be prevented by balancing your water. Using a water test kit or strips remember to achieve Total Alkalinity (TA) levels before balancing your pH levels. More information on how to achieve the balancing act can be found here: Read more about high pH & Alkalinity

Cloudy water – loose particles of scale floating in your hot tub or spa can result in a cloudy water appearance.

Irritation – to the skin and eyes can be a result of high calcium levels affecting the pH balancing of your water.

To ensure your calcium hardness stays within the optimal range for your hot tub or spa, the SpaChem team recommends that you regularly test the total hardness of your water using our 6 in 1 testing strips Palintest 6-in1 test strips (pot of 50 strips).

The total hardness, total calcium levels in my hot tub are too high.

If the levels of calcium in your hot tub water are too high, you will over time experience limescale build up on the fittings, parts and surface of your spa. Which will in the long-term lead to poor functionality and reduce the life-cycle of the affected parts.

In addition, you will also find it difficult to achieve the perfect water balance of your Total Alkalinity (TA) and PH levels which will directly affect the sanitisation of your hot tub water.

The SpaChem scale inhibitor has been specifically formulated to remove the dissolved minerals (namely calcium) from your spa water, which if added on a weekly basis can help maintain your calcium hardness readings and prevent limescale deposits from forming. Use 
Scale Away or No Scale products.

The calcium levels in my hot tub water are too low.

If you are using your hot tub in a soft water area or your calcium hardness readings fall below the optimal level for your specific machine, you will need to include a calcium hardness increaser to raise calcium levels on your list of chemicals required for achieving the perfect water balance and to reduce the risk of corrosion to the heating element and fittings of your spa.

Different manufacturers use varying terminology when talking about calcium hardness products, from hot tub calcium increaser to hot tub calcium chloride and an extensive list between the two. Essentially, they all do the same job which is fundamentally based on the chemical identity of calcium chloride and will increase the level of hardness in your water.

The SpaChem product recommendation for increasing the calcium hardness of your water can be found here: Total Hardness Increaser or Calcium Hardness Increaser.  Calcium hardness increaser can also be known as water hardness increaser and total hardness increaser.

Remember to undertake weekly calcium hardness tests to maintain your hot tub equipment and water levels at peak performance. This management of your calcium levels, combined with balancing your Total Alkalinity and pH levels will maintain the functionality of your water sanitiser. 

Calcium hardness can be added to the spa directly and ensure jets are running, sprinkle the product into the centre of the tub using the recommended measurement, you can also pre-dissolve and add product as well, ensure recommended PPE is worn and manufactures guidelines or followed. Three common water balancing chemicals are Alkalinity Increaser for raising Total Alkalinity, pH Minus for reducing pH levels and pH Plus for increasing pH levels.

Top tip – the quickest way to check if you have soft or hard water is check to see if you have scale build up inside your kettle (ps make sure the kettle not just been boiled and is hot), if your kettle is showing signs of scale or full scaled up then you more than likely in a hard water area, if your kettle is clear then soft water area.

For more advice on water chemistry or recommendations and support about calcium hardness levels contact one of the SpaChem team today on:  02920 280422 or WhatsApp on 07540 184405.