FAQ’s

Due to calcareous content in the water or deciduous plants in the vicinity of the Piscina Biológica® there might be a build-up of sediment at the bottom of the swimming part. Cleaning of this area is recommended every fortnight until monthly through a pool cleaner.

Usually plants do not need maintenance, because the old parts can fall into the water, they will be mineralized with the time and they are part of the feeding of new plants.

Never add any chemicals to the water. It is also not possible or necessary to use any disinfection equipment.

In general it is possible to install a water heating system, but the water in a Piscina Biológica® heats up naturally quickly because of the low water level in the plants. Thus heating is normally dispensable. Generally the temperature should never reach more than 30°C. From this temperature the plants begin to suffer.

The high quality liners we use for piscinas biológicas are polyolefins, a hundred percent recyclable material, a product unique to Piscinas Biológicas®. The material is always welded (not glued!) on site, as a tailor made suit. It is necessary to cover all parts of the liner with substrates or water. The liner has more longevity than concrete.

Often solar or low-consumption pumps are used in Piscinas Biológicas®, and these play a different role than pumps in conventional swimming pools. The goal is to transport water without damaging the ecological balance in it.

No. Many species of fish have a habit of looking for a diet in the mud or near the plants. In a relatively small area and with the aim of maintaining good water quality the fish can not be part of the system.

No. The mosquito species that sting look for other places to lay their eggs. The larvae of these mosquitoes need turbid, nutrient-rich water. And more: In the Piscina Biológica® live several species of other insects (eg dragonfly larvae) that would eat all the mosquito larvae.

Each piscina biológica® is unique and designed for the site. But all have in common the configuration of the space, with a part destined to the bath of the people and one destined to the purification, that is, for the plants. It will not always be avoidable for a frog to appear in the swimming compartment, but usually they live in the area of the plants where they most easily find shelter and food.

The plants are created for the purpose in an own nursery in the Algarve. We have more than 130 species of native aquatic plants, exclusively produced for our projects. The photo shows a part of the nursery, which is, in terms of the variety and diversity of species it produces, the largest in the Iberian peninsula.

Many of the plants in a piscina biológica® look beautiful all year round because they are vivacious plants. Many of them turn green even in winter, at least in the south of the country. In cold, snowy lands, in winter there is another situation. The plants look brown, but grow back in the spring. Few species, such as water lilies, are hibernating beneath the surface of water, with no visible leaves, but in spring they again throw floating leaves and flowers on the surface of water.

We never have to replace the plants, because the plants are all alive, they grow again in the spring and, in addition, they create new generations.

Aquatic plants produce oxygen like terrestrial plants. Oxygen is soluble in water. The amount of oxygen within the water depends on the temperature thereof. In the afternoon, after a few hours of light, photosynthesis has produced so much oxygen that the limit of mixing water and oxygen will be exceeded. This means that oxygen bubbles start to come out of plants like carbon dioxide in a glass of sparkling water.

In an oxygen-filled aquatic environment there is no hypothesis that pathogenic organisms multiply in excess.

The water is transparent and complies with all the standards required by law for bathing water quality.

The water quality of the Piscina Biológica® depends greatly on the water quality of the first filling. We can not use all waters, e.g. those contaminated by microorganisms whose levels already exceed standards for bathing water. Also the chemical composition has to be below certain values, especially those of the nutrients for plants. Any necessary pre-treatment has to be defined at the stage of project design.

Therefore, a water analysis is mandatory before beginning the planning of the Piscina Biológica®.

No. But the oil film floating on the surface of the piscina biológica® looks very ugly. To avoid this effect, and to reduce the entry of harmful microorganisms into the water, it is mandatory to take a shower before entering a piscina biológica®. As well for hygienic reasons, each project has to have a shower near the entrance for all people to clean their skin before showering.

Every place with more or less deep water is undoubtedly a potential danger for children or other people who can not swim. Compared to conventional pool basins a Piscina Biológica® usually has a plant’s margin and less sloping banks. There are nets and other types of fence to have a greater safety for the kids. But better than any technical solution, it is the accompaniment of the younger ones by the parents.

At the stage of designing a Piscina Biológica® one should always think of all members of the family. Therefore it is essential to provide, yet in planning time, all the information about the future users of the Piscina Biológica®.

Many of the hundrets of Piscinas Biológicas® existing in Portugal are projects for private homes. One can easily understand that not all owners like to receive visitors. But there are Piscinas Biológicas® in tourist houses. It is possible to spend there nice “holidays with Piscina Biológica®”.

Costs vary greatly, depending on the size of the installation, materials and finishes chosen. Concrete structures are more expensive than waterproofing with a special liner – after all the most common method for building pools with biological treatment.

With the base in about 200 constructed projects of Piscinas Biológicas® in Portugal one can consider an orientation price per square meter of about 135 Euro (excluding only the water costs of the first filling).