Factors That Affect the Color of Pool Water

Probably the most common issue experienced by swimming pool owners. We have been told, numerous times, that the pool water turned green suddenly, overnight. There are various reasons why this can happen.

Α) Low values of free chlorine, due to:

• Insufficient amount of disinfectant. This can occur by cause of an unexpected event, such as a storm, high number of people using the pool, strong winds, high temperatures, etc. All of the above, influence the levels of free chlorine, since its consumption is increased in order to handle the extra workload. Hence, whenever we experience situations that disrupt the chemical balance of water, we need to be quick on our feet, and continuously test the disinfectant levels.
• High values of isocyanuric acid. We already know that, as the season ends, values of isocyanuric acid are quite high. As a result, chlorine hyper-stabilizes in the water and does not kill algae, bacteria and microorganisms. In this case, the pool’s chlorine needs are highly increased.

B) Poor filtration:

• Water filtering is factoring around 70% of the water’s quality, so it is extremely important that our means of filtration are in good condition and effectively filter a large part of the water’s load. It is very common in sand filters, for the sand to solidify and form biofilm (microorganism colonies and canals) reducing its effectiveness. The solution to that problem is substituting sand with NatureWorks glass solution, which does not form biofilm or canals, does not solidify and has a higher life span compared to sand.

Nature Works Filter Media

C) High value of phosphates.

• It is certain that phosphates exist in the pool water, through various sources. Algae feed on phosphates, which help on their development, and as a result, the water turns green if the appropriate conditions are met. The solution to this problem is the use of a specialized Starver X chemical, which removes all phosphates in the filter and we do not allow algae to grow uncontrollably. Another added benefit of using Starver X is reducing the amount of disinfectant you need, improving its action and, consequently the concentration of isocyanuric acid.

D) High pH:

• An increase in pH is one of the reasons that can cause pool water to turn green. The high pH is mainly due to some severe weather phenomenon, high load of bathers in the pool, high alkalinity of the water, etc. When we have high pH levels in the water then the growth of micro-organisms, bacteria and algae is favored and at the same time the disinfecting effect of chlorine is dramatically reduced to deal with these loads, resulting in the water turning green. So it is important, as we mention in the article about pH correction, that we first measure the alkalinity and correct it if necessary, and then proceed to the pH correction.

E) High temperature and solar radiation:

• High temperature and solar radiation negatively affect the disinfecting effect of chlorine, especially sodium hypochlorite. We also find this during the summer months, where consumption is considerably higher. Finally, the high temperature also helps the growth of microorganisms, bacteria and algae.

To avoid this unpleasant problem we should maintain the chemical balance of the water and make the necessary measurements. At the same time, it is very important to maintain the good condition of the mechanical equipment as well as the filtering medium with their proper maintenance.