4 Tips to Maintain Good Swimming Pool Water Quality

A swimming pool is one of the more challenging engineered water systems to maintain in a safe manner. Good maintenance involves both the inside and outside of the pool, along with the general pool area and the equipment involved. You also need to be sure the pool water quality meets minimum safety standards, as it’s likely lots of people will be using it throughout each day.

A swimming pool can potentially pose a big health hazard if it is not properly protected, cleaned, treated, and maintained regularly enough. As far as pool water quality goes, you need to be sure you attain the right balance of chemicals to inhibit the growth of waterborne pathogens such as Legionella, Pseudomonas and Cryptosporidium.

In this article, we’ll cover four important factors you should focus on to achieve and maintain the best water quality for your swimming pool.

1. 1. Maintaining the correct pool pH levels and alkalinity
   2. Optimising calcium hardness levels
   3. Total dissolved solids (TDS)
   4. Dealing with minerals that stain or discolour

1. Swimming pool water quality, pH levels and alkalinity

Typically, the pH level of your pool should be maintained between 7.0 and 7.4. (ideally 7.0 – 7.2) with a chlorine residual of 1.5 – 3mg/l (for all chlorine based disinfectants except cyanurates).

We can include alkalinity in this section as well, as it dovetails nicely with the pH element. If you achieve the best balance for the water in the pool, it should be able to resist an attempt to change the pH level. Chlorine is commonly used to sanitise pool waters, and if the alkalinity is measured somewhere between 80 and 200ppm (parts per million), you should be able to achieve this.

2. Optimising pool calcium hardness levels

The more calcium there is in the water in a swimming pool, the more likely it is you will see scale forming around the edges of the pool. It can also cause the water to become cloudy. Conversely, if the calcium levels drop too low, it can cause corrosion to fittings and fixtures within the pool. Therefore, it makes sense to visually check the water quality, check the sides of the pool for potential scale, and for signs of corrosion to any fixtures, fittings, and parts of the water system used in the pool.

You can treat unbalanced calcium levels by adding a sequestering agent (also known as a chelating agent) to the water. Ideally, you should aim for calcium levels of between 80 and 200ppm.

3. Levels of total dissolved solids (TDS) can affect water quality

This sounds horrific, but while dissolved solids can include contaminants we can leave to the imagination, they can also include the minerals we’re about to cover, and even salts.

When conducting a pool risk assessment, it is good practice to identify the TDS levels in the mains water supply feeding the pool. This is used as a baseline, whereby the TDS levels for the swimming pool should not be any higher than 1000ppm (parts per million) when considering the mains level. So, whatever you find is correct for the mains, you can work out the maximum safe level for the pool from there.

If the levels go higher than this amount, you may notice problems with water quality, foaming on the surface of the water, and difficulties in using a sanitiser to get the best results. Knowing the TDS for the pool therefore relies on understanding what’s in the mains water supply first.

4. Minerals that may discolour the water or stain the pool

Earlier we mentioned cloudy water caused by calcium, but it’s possible to have certain minerals in the water that can turn it different colours. Some minerals do this on their own, while others react with chemicals in the water. For example, copper can cause surfaces in contact with the water to go anywhere from green to blue to black. This includes people using the pool. It doesn’t cause cloudy water though, so if you find a green cloudy tinge has appeared, this would likely be caused by algae instead.

Another example is iron deposits in the water. These won’t cause any discoloration on their own, but when they encounter chlorine, they react and turn red or orange, causing the water and the surfaces to change colour.

You should take a proactive approach and focus on preventing such staining rather than combating it when it appears. The presence of such minerals should be highlighted as a potential risk when conducting a pool risk assessment. In many cases, the biggest risk for introducing minerals into the pool occurs when filling it with water. To this end, you may need to add a sequestrant to combat any unwanted mineral content when filling the pool. This should prevent any issues caused by staining pool surroundings or discolouring the water. While it may look fascinating, it can be difficult to remove any stains around the pool, so it’s better to make sure they’re not there to start with.

Knowing the best levels for your own swimming pool

You can see that by knowing the best levels for various elements in the pool water will help you maintain those levels. You can test the water to determine whether it is within safe parameters. You can also proactively treat the water when adding it to the pool or when cleaning it. This will ensure the minerals, pH balance, and other factors are kept at their optimum levels, so good water quality is maintained, equipment life is extended and everyone using the pool can do so safely.

Expert pool water quality testing

Water Treatment Services offer a comprehensive range of water quality testing and laboratory analysis solutions to support owners and operators of swimming pools, spas and hot tubs. Our experts can provide advice and support to help you identify the most appropriate strategies for the on-going management of your pool facilities to keep them safe and in tip-top condition.

With offices in London serving the South and South East England, Manchester (North West), Birmingham (Midlands), Bristol (South East England and Wales), Leeds (North and North East) and Glasgow (Scotland), supported by regional teams of specially trained technicians, in-field specialists and consultants we can offer professional, cost effective water management and laboratory analysis solutions across the whole of the UK and internationally.

Contact us today to learn how our expert water management solutions can help keep your pool waters clean and safe to use.