[C754]Cloudy Water In Aquarium

The fishes that we keep in our aquariums originate from all over the world. It is therefore necessary for the aspiring fishkeeper to have an understanding of how the chemistry and quality of the water varies from region to region. You will need to understand and be able to alter your own local water to suit the needs of your fishes. You MUST regularly monitor your water to guard against any build up of harmful pollutants, as well as its general condition.

Natural bodies of water, such as lakes and rivers, are by nature very stable environments, their large volumes of water counteract any changes in water quality, and it is this dilution effect that makes such changes hardly noticeable. Tropical freshwater fishes have evolved to live in these stable conditions, and are therefore very susceptible to any change they may encounter in water chemistry.

Although we like to regard our aquariums as a small-scale reproduction of life in a lake or river, we must consider the much smaller volume of water our fishes have to live in. Any changes in water chemistry will have a greater impact in the aquarium than in nature, due to a much lower dilution effect. Fishes will detect even the smallest decline in water quality, and will often show signs of irritation and stress.

As you probably know water is a compound of hydrogen and oxygen, at the ratio of 2:1, hence H2O, and although life is dependant on water, pure water will not support life. Water must contain certain salts if it is to support life at all. Fortunately, water is highly adept at dissolving gases and solids, and it is this ability to readily dissolve other substances that makes it able to support life (water will also readily dissolve pollutants, which must be controlled). It is because of this capacity to dissolve numerous substances in large amounts that pure water rarely occurs in nature.

As water falls to earth as rain or snow it will absorb from the atmosphere varying amounts of carbon dioxide and other gases, as well as traces of organic and inorganic matter, upon reaching the earth's surface, the water will follow two paths. Some of the water will infiltrate the soil, a part of which becomes soil moisture, which will evaporate directly, or be used by the roots of vegetation. Water that overcomes these forces in the soil profile will percolate deeper and become a part of the groundwater reservoir, the surface of which is known as the water table.

The other path that rainwater will take is over the surface, which is termed as surface run off, and will run directly into streams, rivers, and landlocked bodies of water, such as lakes. Most natural waters contain dissolved salts, which are consequently found in tap water. Natural water will also contain suspended and dissolved impurities, which is why it must be treated before it is fit for us to drink.

The amounts of salts dissolved in the water determine whether it is hard or soft. Water that is in constant contact with substances such as limestone or chalk tends to be hard, whereas water running over sandstone or granite for instance, is likely to be soft.

Hardness of natural water is caused largely by calcium (Ca) and magnesium (Mg) salts and to a small extent by iron, aluminium, and other metals. This is referred to as General Hardness (GH), or Total Hardness, and is a measure of all the dissolved salts in the water.

General Hardness influences Calcium levels in the blood, and the osmotic regulatory systems of fishes are affected by concentrations of dissolved salts. High levels could irritate gill membranes, they may look slightly swollen, and the fishes may be seen flicking or rubbing in the water.

It is necessary to test for General Hardness so that it matches the original habitat of the species being kept. Hardness is usually expressed in terms of the amount of calcium carbonate (CaCO3) present in solution, and is normally measured as parts per million (ppm).

If General Hardness is too high make sure there are no calciferous materials in your water, such as coral, lime, or chalk. Alternatively water-softening products are commercially available.

If GH is too low add calciferous materials such as pieces of limestone into your aquarium; or a little coral gravel into your filter; don't add too much at one time, and monitor until desired value is reached.

Carbonate Hardness (KH), or Temporary Hardness is principally composed of bicarbonate ions (HCO3) and carbonate ions (CO3), and has the capacity to neutralise an acid, this is known as the buffering capacity. Carbonate Hardness stabilises water pH.

The immediate aspect of this is that aquariums with soft water are more likely to suffer from the phenomenon known as pH crash. This is when the pH abruptly drops, and for the newcomer to the hobby, it would seem like there was no apparent reason.

Carbonate Hardness (KH) is expressed in terms of the amount of calcium carbonate (CaCO3) present in solution. The test is similar to the GH test, but with a different reagent (the substance used to react with your water in the test tube to obtain a result).

The hardness and pH of your tap water supply is the first thing you should evaluate, knowing this will enable you to choose fishes that would be suited to your water conditions. Alternatively you will have to adjust the chemistry of your tap water to suit the requirements of the fishes that you choose.