Green-colored water is caused by a phytoplankton bloom and no immediate effect against this problem can be expected even if an entirely new filtration system is added to the aquarium. It would be more effective if the existing filter is temporarily replaced with a filter used on another tank that contains an adequate amount of filter bacteria.
It would be best if a filter containing abundant bacteria colonies is installed in addition to the existing filter for the planted aquarium with a greenwater problem, this method is called Jump Start Method, although it might be difficult for hobbyists to do so in practice. Another remedy is to use UV Lamp into the aquarium. Please try it.
In Nature Aquarium, aquatic plants grow in a tank and play a role in water purification. Beneficial microorganisms such as aerobic bacteria and protozoa in the external filter require oxygen in the water for their activity. It can therefore be said that microorganisms are more active or propagate at a higher rate with a higher concentration of oxygen. The external filter containing a lot of filter media has a powerful filtration capacity but, at the same time, it consumes a large amount of oxygen for microbial activity. Oxygen is always sup•plied to the water through the water surface, and on top of that, a greater amount of oxygen is generated through photosynthesis of the aquatic plants. This means the aquarium in which lush aquatic plants grow and vigorously perform photosynthesis is favorable to the activity and propagation of aerobic bacteria. In such an environment, organic matter causing water contamination can be captured and consumed by protozoa and they are further decomposed and oxidized by aerobic bacteria.
The role of the aquatic plants in water purification is not only to supply oxygen to the water. Aquatic plants grow by obtaining carbohydrates and energy through photosynthesis but are unable to perform adequate synthesis of amino acids and pigments essential for their growth just by this process. For this reason, the aquatic plants need to get their nutrients from the water. Nitrogen content and phosphoric acid cause water contamination but at the same time they are also nutrients to be absorbed by aquatic plants. Once the aquatic plants start growing vigorously, a large amount of nutrients are absorbed by the plants, by which the water in the tank is purified.
Aquatic plants absorb nutrients not only via their roots but also through their leaf surface. Therefore the environment with a large amount of stem plants with submerged leaves has a high water purification capacity via both the supply of oxygen and absorption of nutrients. Nitrogen content and phosphoric acid are often not detected in the aquarium under such a condition. Growing aquatic plants healthily can lead to water purification
The basic concept of Nature Aquarium, that is, making use of diverse living organisms including aquatic plants, mud snail and Cardina japonica for water purification. Although it is impossible to reproduce the natural ecosystem exactly as it within the limited space of a tank, the essence of the ecosystem can be extracted and rebuilt in an aquarium.Biological filtration, which is regarded as the most important process in the filtration system of Nature Aquarium, is a method of filtering water with the help of microorganisms, a representative decomposer in the ecosystem.
In a natural aquatic environment, microorganisms such as bacteria and protozoa are present on the mud and sand at the bottom of the water as well as on stone surfaces. In the aquarium tank, too, they are found on the surface of the substrate and stones, but their water filtration function is not powerful enough since the tank area to microorganisms can attach themselves is very restricted. To solve this problem, an independent external filter is used for the aquarium to produce more bacteria so as to achieve a high filtration capacity.
The external filter contains filter media such to which microorganisms such as bacteria and protozoa adhere. Since more bacteria can adhere to a larger surface area, materials with large surfaces and good water permeability are ideal for biological filtration. The filtration capacity of microorganisms declines if the filter media are too fine or stuffed too much to the extent that water permeability is affected.
To perform biological filtration, it is necessary to ensure good water permeability so that the filter media surface is exposed to the water containing rich oxygen in order to optimize the important functions of microorganisms that need oxygen such as aerobic bacteria and protozoa. In nature, too, water quality can easily deteriorate in the aquatic environment with stagnant water where oxygen is lacking. To keep the water in a good condition, it is crucial that the water contains adequate amounts of oxygen and is kept in motion
When only fish are kept in the aquarium, the water continues to get contaminated unless water change is performed. By contrast, natural aquatic environments originally have their own water purification mechanism involving diverse living organisms. In fact, fish are a contributing factor to water contamination even in natural aquatic environments. However, water purification takes place at all times there by way of decomposition of organic matter and ammonium released from the fish feces by countless decomposers present at the bottom of water and other locations. Besides microorganisms, including bacteria and protozoa which are well-known decomposers, crustaceans such as Cardina as well as shellfish such as mud snail also help in water purification as decomposers in a natural environment.
What is important in the natural ecosystem is biodiversity. Swift decompositlon of water-contaminating organic matter is made possible by the presence of diverse species of decomposers other than microorganisms. For instance, the mud snail filters the water through its gill, and it also hardens algae, bacteria and organic matters with its mucus. A part of the hardened materials is consumed by the mud snail as food and the remainder is deposited at the bottom of the water. The deposited organic matter will eventually be eaten by crustaceans such as Cardina and refined through this process, allowing easy decomposition by microorganisms. Cardina and mud snails also feed on algae grown on emergent plants. After the algae on the plants have been eaten by these species, the algae start to grow again and absorb nitrogen and phosphorus in the water as nutrients.
In this way, water is further purified via repeated elimination and re-growth of the algae on plants. In addition, it is widely known that emergent plants such as reeds help to promote water purification by absorbing nitrogen and phosphorus in the water through their roots.
