Turbidity is a measure of how cloudy water is. Sometimes also termed water clarity, turbidity is often used as a measure of the sanitary quality of water and often indicates that filters are not working properly.
Turbidity is present in a variety of applications. Below we outline where you may find turbidity and why it should be monitored.
Turbidity is used to measure the clarity of pools and spas. Clear water is essential not only for the aesthetics of the pool, but also for safety reasons so that swimmers, lifeguards and camera systems can see through the water.
The turbidity of pool and spa water should be below 0.5NTU. This level of turbidity is not visible to the naked eye; a meter designed for turbidity measurement should be used to test the water weekly.
If the turbidity of the pool water increases, this can indicate a problem with the pool chemistry and / or the filter system. To find out what cause’s turbidity in pools, acceptable turbidity levels and how to measure turbidity in a swimming pool, read our support article measuring turbidity in swimming pools.
Turbidity is a critical parameter for drinking water; it is one of the most important and regular tests done by drinking water companies. Turbidity monitoring is used to measure water processing efficiency in drinking water. Turbidity changes in drinking water can be caused by a multitude of things; it can indicate that the filters are not working correctly, that there is a problem with the water, ineffective disinfection or poor coagulation and flocculation.
The WHO set a limit that the turbidity of drinking water shouldn’t be more than 5 NTU, and should ideally be below 1 NTU. Most UK water companies aim to reach a target of less than 1NTU at the drinking water treatment works. Turbidity testing is widely performed by water companies, read our case study on the Sutton and East Surrey water company to find out some of the turbidity challenges water companies face and how they overcame them using Palintest equipment.
Often the turbidity of water is used to assess water quality prior to release into the environment.
Turbidity changes in wastewater can indicate that filters are not working correctly or that there is a problem with the water chemistry. It could indicate ineffective disinfection or poor coagulation and flocculation.
Palintest offers a number of solutions for turbidity testing, all of which are suitable for different users. Turbidity tubes are used for a quick and approximate indication of turbidity. For a more advanced test the Turbimeter Plus can be used. It uses unique Quadoptix Technology allowing multiple validations of results for greater accuracy. The Turbimeter Plus is also available as part of the Turbidity and Ammonia Combined Kit or Turbidity and Chlorine Combined Kit. These kits are ideal for service professionals and have been designed for field use.
Turbidity of water is affected by a number of factors, including the presence of dissolved and suspended solids, size and shape of particles and the composition of particles.
High turbidity means that there are a lot of particles suspended in the water and light cannot pass through the water.
NTU stands for Nephelometric Turbidity Units; the unit used to measure the turbidity of a liquid.