Chemical disinfection in the hybrid pool (often wrongly sold as a bio or eco pool)
Hybrid pools use a diﬀerent form of disinfection that allows resistant aquatic organisms to survive.
This allows for the use of hardy riparian plants to create a natural look. But biology is not the basis of water puriﬁcation, as most live is killed by the disinfectants. Plants are just decoration.
These disinfection techniques are commonly used in hybrid pools:
UV Light: Part of natural sunlight that strongly aﬀects living tissue. It causes us sunburn and the death of viruses, bacteria and algae. UV lamps are used in ponds to avoid green cloudy water caused by small algae. In aquarium or aquaculture with large amount of ﬁsh, UV can be used to reduce the pressure of pathogens. In nature, this only happens in the ﬁrst few centimeters of the surface, while pathogens and algae in the lower water layers are eaten up by zooplankton. UV light also kills zooplankton... the entire food chain and biological puriﬁcation is disrupted. UV light does not reduce or ﬁx nutrients. The nutrients ﬁxed in the biomass of algae, bacteria and zooplankton are released again and instead promote the growth of ﬁlamentous algae. UV light leaves no chemicals in the water and doesn't kill life outside the lamp. Therefore, in a situation of disruption of the biological system, temporary use is accepted. (FLL, German standards for planning, construction and maintenance of NSPs and basis for various other national standards).
The energy consumption of UV lamps is relatively high, on average higher than the total energy consumption in a biological pool.
Copper: essential to life in small amounts, quickly toxic in higher concentrations. Most algae killers for pools and ponds are copper based. It can be added as a salt (e.g. CuSO4) or by electrolysis. Copper destroys the structure of algae, both planktonic and sessile, so it is also eﬀective against thread algae. It also kills many bacteria and other microorganisms in the water and bioﬁlm (ﬁlter), aquatic snails, larvae and sensitive ﬁsh. Copper stays in the water and accumulates in the sediments. In countries with more restrictive legislation, copper is strictly forbidden in public swimming pools (both natural and chemical). Copper is an absolute no-go in a natural swimming pond/pool. Tall plants are much more resistant to copper, which allows them to be used as a decorative element in hybrid ponds, giving them the visual aspect of a biological system.
Silver: Silver, like copper, is a heavy metal with lethal eﬀects on small organisms. It is also used in the form of electrolysis. Absolute no-go in biological cleaning.
Hydrolysis: This is the technique used in "salt water pools". An electric ﬁeld creates "radicals" of chloride ions from the salt dissolved in the water. At higher voltages, the splitting of the water molecule can even produce oxygen and hydrogen radicals. The radicals are extremely aggressive to all surfaces and quickly kill small life forms. The chloride reacts with nitrogen (from skin, hair, urine, all biomass) resulting in carcinogenic by-products like trichloramine that build up in pool water.
There is much more reactive biomass and nitrogen present in a hybrid pool than in a chlorine sanitized pool, resulting in an even higher production of these dangerous by-products! Absolute no-go for biological water treatment.
pH control with hydrochloric acid, like in the salt water pool, to ensure the disinfection eﬀect.
A hybrid pool is neither a NbS (nature-based solution) nor a swimming pond or natural pool. All poisons that can be used in a hybrid pool are legal for private use. In terms of water treatment, the hybrid pool is very similar to a classic pool, although the appearance can resemble a biological swimming pond. It is an alternative to Cl-disinfection and biological .
It is completely wrong to sell a hybrid pool as a swimming pond/natural pool! This is greenwashing and unfair competition.