Algae per se are not dangerous, but the bacteria feeding on them certainly are. They are unsightly, ranging from green to blue or black. Another typical complaint is burning eyes. These are either caused by a low level of alkalinity, a high level of calcium hardness, a PH too high or too low or a combination of these factors.
Chlorine smell is caused by a lack of chlorine in the water, not abundance. What happens is what little chlorine is there it reacts with human waste such as urine ammonia (not a pretty thought, but this is what happens) or simply sweat and produces smelly chloramines.
General cloudy water is caused by an array of factor such as inadequate levels (too high or too low) of PH, chlorine, calcium hardness, alkalinity, metals, high density of micro-particles, dirty water filters.
Last, but certainly not least, are multiple water borne illnesses caused by bacteria and viruses. This is the most important aspect to take into account when dealing with swimming pool maintenance. Some of the diseases born out of a contaminated pool are very serious, like Cholera, Typhoid, Hepatitis or Salmonella. Other common illnesses include Dysentery, Gastroenteritis, Giardiasis and Dermatitis.
In fact, most swimming pool viruses have become more and more resistant to treatment over the last few decades, making a good pool maintenance routine mandatory so as to prevent these problems to arise in the first place.
The only problem is that often swimming pool maintenance can be problematic for the average pool owner without chemistry knowledge, or too expensive, or both. Running costs could range from few $hundred to even few $thousand a year, whereas in fact with ta little knowledge it is possible to cut these expenses and maintenance time to a tiny fraction with a cheap but effective swimming pool maintenance routine.
The only problem is that often swimming pool maintenance can be problematic for the average pool owner without chemistry knowledge, or too expensive, or both. Running costs could range from few $hundred to even few $thousand a year, whereas in fact with ta little knowledge it is possible to cut these expenses and maintenance time to a tiny fraction with a cheap but effective swimming pool maintenance routine.