Water Care for Fish

Water care refers to the process of monitoring and maintaining water quality in an aquarium or aquaculture production system. This is important because it facilitates transport, respiration, hydration, uptake of ions and feeding in fish.

Water care includes the following procedures:

1. Measuring Water Quality: Through using chemical (manual or mechanical) or automatic testing techniques.

2. Replacement of Water: The replacement of a portion of the medium regularly.

3. Maintaining Water Quality: This can be achieved through physical, chemical and biological filtration.

Measuring Water Quality
To determine water quality, several components of the water are tested using a colour change test. Regular tests for pH, Ammonia, Nitrate, Nitrite, Total Dissolved Solids (TDS) and salinity are regularly conducted in closed aquaculture systems to maintain the optimum conditions required for efficient growth of livestock. These tests are typically conducted several times an hour in an aquacultural production system, as they are important in detecting potentially hazardous circumstances such as the death of a fish that will rapidly increase ammonia levels and may result in a domino effect. Temperature is homeostatically maintained through a thermoregulator as rapid fluctuations in water temperature can be fatal to fish.

Hence these tests are extremely important and are therefore typically conducted mechanically in larger production systems using automatic refractometers and electron probes. However for smaller isolation tanks or aquariums of pet fish it is typically easier to conduct manual tests on temperature, pH and other dissolved ion and solids as it is more cost efficient.

To conduct a test on water quality
Organic Ion Analysis: Take several vialsfull of water from the system and conduct tests using API’s Freshwater Aquarium Kit that gives a comprehensive analysis of pH, Nitrate, Nitrite, Ammonia and Phosphate.

Salinity: Use a hydrometer (placed in water for scale) or a refractometer (place a small sample on clear glass opening and read).

Replacement of Water
In a closed system such as an aquarium the addition of food will inevitably result in the production of toxic nitrogenous wastes. Hence 25% of the water in a closed system has to be replaced every week to maintain water quality, which will optimize growth in aquaculture or coloring/behavior in the ornamental trade. In a smaller scale aquarium, tap water is treated with chemicals such as buffers and dechlorinators to provide the ideal enironmentt for the fish housed. For example Angelfish perform best at low pHs (6-6.5) with little dissolved ions whereas other Cichlids prefer high pHs and 'hard water' (water high in dissolved minerals).

Filtration: Maintaining Water Quality
A filter will reduce the impacts of wastes by breaking them down into less toxic compounds and plants can be imbued into the system to reduce ions of oxidised nitrogen (Nitrate and Nitrite) and Ammonia.

In an aquarium, tap water is sufficient for most freshwater species but must be left for a few days to let the chloride atoms (that are harmful to fish) dissipate. Alternatively several chemicals can be added to the water to catalyse this process. The ion concentration can be easily manipulated through the addition of salts and the pH adjusted through the addition of buffers, carbonates (increase pH) or sulfuric acid (decreases pH).

The basic components of a filter include: From Left to Right: Filter Wool, Sponge, Ceramic Noodles and BioBalls ]] '''Do you feel ready to take the quiz on water care for fish? Click Here!'''
 * 1) Wool: Should be placed at the front of a filter (water input) as they catch most of the incoming detritus from the aquarium (uneaten food, faeces and rotting vegetation). They are depleted quickly and must be changed every two weeks or when they turn dark brown. This is known as physical filtration as it physically removes detritus from the aquatic system.
 * 2) Sponges: Captures smaller particles and houses many microbes that assist in their breakdown. Can be reused but must be rinsed in aquarium water every few weeks to reduce its accumulated waste. This is a combination of physical and biological filtration as it trapes small particles but also facilitate nityficationn.
 * 3) Ceramic Noodles/Plastic BioBalls: Has high surface area that houses many beneficial micro-organisms such as nitrifying bacteria that break down ammonia (highly toxic) to nitrite (tolerable in low ppm) and nitrate (tolerable in ppm). They should be disturbed every month to remove excess sedimentation and organic waste. They should be placed near the rear of the filter and be partially replaced every four years (a quarter of the total amount) as they eventually become saturated with organic waste hence reducing efficiency. This is known as biological filtration as biochemical processes are encourage to improve water quality. The BioBalls provide the benefits described above but are more easily cleaned and last longer.
 * 4) Charcoal/Slow Releasing Buffer/Other Functional Items: Are typically placed at the rear of the filter near the rotor. This is to prevent early contamination with organic wastes for longevity. This is known as chemical filtration as chemicals such as charcoal or buffers are introduced into the system to improve water quality.[[File:Filter_Media.png|centre|thumb|510x510px|