How to test and rise the hardness of swimming pool water?

The appropriate hardness of pool water is 150-1000 ppm. The hardness of pool water is very crucial, mainly due to the following reasons:

1. problems caused by too highhardness

Appropriate hardness helps maintain the balance of water quality, prevent mineral precipitation or scaling in the water, and thus maintain the clarity and transparency of the water. High hardness water is prone to form scale on equipment such as pipelines, pumps, and filters, which affects the normal operation of the equipment and shortens its service life.High hardness also reduces the effectiveness of algicide products.

2. problems caused by too low hardness

Low hardness water may cause corrosion of concrete pool wall. Therefore, by testing and controlling the hardness of pool water, pool can be protected from damage and its service lifeshould be extended.

3. Enhance swimming experience:

The hardness of pool water directly affects the comfort and experience of swimmers. Appropriate water hardness can make swimmers feel more comfortable and enjoyable, increasing their satisfaction and loyalty to swimming activities.

In swimming pool, we usually use three methods to testthe calcium hardnessof the pool water.

1. Total hardness test strips

It is very simple to use:

1). Use specialized total hardness test strips, immerse the test strips in the liquid to be tested for two seconds, and then shake off the solution on the test strips.

2). After waiting for 15 seconds of reaction, compare with the color card and determine the hardness of the water based on the color change of the test paper.

The test strips are very convenient to carry, very simple to operate, and the cost of a single test is very low, but comparing colors requires a certain amount of experience.

2. Chemicalreagents

The test is similar to the test strips. Add the pool water and chemicals into the test tube according to the operating instructions, and then compare them with the standard color chart. The advantages are similar to test strips, but the test usually could obtaina more preciseresult.

3. Calcium Hardness Colorimeter

Follow the operating instructions of the instrument, add the pool water and chemicals into the testing tube and then the instrument will directly show the hardness value of water after testing.

Calcium hardness colorimeter are very accurate because they do not require visual comparison of colors, but the colorimeteris expensive and difficult to carry.

If we need to rise the hardness of pool water, the common way is as below:

1. Add a higher hardness water source:

If conditions permit, the overall hardness of the pool water can be improved by partially changing the water and adding a harder water source.

Attention: This method requires ensuring that the water quality of the newly added water source meets the standards for pool water use, and pay attention to control the water changing ratio and adding amount.

2. Use calcium chloride to rise the hardness:

Calcium chloride is one of the commonly used agents to increase the hardness of swimming pool water. It can directly provide calcium ions to water, thereby increasing its hardness.

Usage: Calculate the amount of calcium chloride to be added based on the pool’s water volume and the required hardness value, and evenly sprinkle it into the pool. Each1.1 g of anhydrous calcium chloride can increase the hardness of 1m3 of pool water by 1ppm.

Attention: When adding calcium chloride, ensure that the circulating filtration system is turned on to allow the agent to be evenly dispersed in the water.