Studies that have been done on chlorine in swimming pools and its influence on the health of people using the pools. The main research seems to link lung damage as a result of daily swimming or being at the pool side daily as linked to the equivalent lung damage as found in heavy smokers. Links to asthma are conjectured but not proven. http://news.bbc.co.uk/2/hi/health/2943290.stm

Dry skin and red eyes is most peoples experience of a chlorine pool, and chlorine allergies are becoming increasingly common.

Conceptually there are problems with chemical pools as well. The water is clean and purified due to the high concentration of chlorine, but by no means is the water clean. It is a nutrient soup of whatever has found its way into the pool over the past while, which is sterilized into being inert to prevent naturally occurring organisms from processing what they see as natural nutrients. Thus if somebody urinates in the pool; nothing processes the urea and it can remain present in the pool for years. The chlorine neutralizes the bacteria that try to process it naturally to break it down into its more basic organic components. No mechanism is in place to physically remove any organic compounds from the water. Over many years more and more water is added to the pool, which evaporates away, and the nutrient soup becomes richer and richer. The amount of chemicals needed to be added to the pool increase as times go on and the neutralized organic soup becomes thicker and thicker. You can see this in many long term established chlorine pools where the water is a cloudy white colour, and the chemical deman from the poll gets greater and greater.

Another health risk with a chlorine pool is that should the pool have insufficient chlorine, then the nutrient soup and the presence of ecoli bacteria can quickly lead to a very unhealthy and unhygienic environment which it is not safe to swim in.

In a wetland pool the water is stripped of nutrients and is clear, clean and healthy. In this time of water uncertainty, having a body of potable water in your garden is not a bad investment. In Kensington in 2009 the water supply was cut off for 2 weeks, and the the owners of the Kensington pool used that water as drinking, cooking and washing water for those 2 weeks whilst their neighbours really battled and mostly relocated.

The other big issue dividing wetland pools and traditional chlorine pools is around the question of the design of the pool. A chlorine pool can be a neutral container of any shape or volume, and is merely a receptacle for water and people swimming in them. A wetland pools, however, is a living, breathing ecosystem. The way that the water flows through the system and the wetland has a direct impact on the water quality. The presence of waterfalls, fountains or other forms of aeration can dramatically affect the amount of algae in the pool.

A conventional chlorine pool is one which gives pleasure during the approximately two per cent of the year when somebody is swimming in it, and is a bit of a drag the rest of the time. It is perceived of and is meant to look like a clean kitchen sink - monolithic and sterile; wheras a wetland pool is also a garden, and becomes a part of the broader garden, with plants that grow and flower and reflect the changes of the season. It also attracts wildlife and is the favourite water bowl of every dog. The weland pool is fundamentally life affirming.

Most peoples experience of a chlorine pool is one of fighting against nature, whilst in the rest of the garden one is trying to work with nature, and the contradiction of this is often evident in many gardens. Similarly, the water from a wetland pool is healthy for plants, birds and animals, so water splashing from the pool will not poison the lawn or adjacent plants. Large paving surrounds to pools are therefore not necessary. The pool water is also not corrosive so paving areas and nearby steel window frames do not suffer the corrosion often experienced next to chemical pools.

To summarise, a chemical pool is about being in a laboratory, fighting nature, wheras a wetland pool is about being in a garden, working with nature.