Everyone who has owned a fish tank has had a problem with algae, a microscopic plant that can cover the glass, plants and ornaments with a green coating. Algae comes in many forms and colours. Most often it is introduced into the aquarium by the addition of new, live plants or simply by the air. Algae, while unsightly, is easy to get rid of and easy to avoid in the home aquarium. If you are maintaining the aquarium properly, you should be doing water changes about once per month. By removing 25% of the water, you are removing minerals, wastes and ammonias that can harm your fish. You are also removing algae suspended in the water and refreshing your tank. You could also take this opportunity to remove the artificial plants and ornaments so they can be washed. The sides of the glass can be sponged, using a soap free sponge.
There are over 25,000 species of algae known to date. Like all plants, algae can make its own food through the process of photosynthesis. In the presence of light, carbon dioxide from the water is taken in and exchanged for oxygen. In the dark, however, the plant takes in oxygen and releases carbon dioxide into the aquarium. In an aquarium with a heavy algae growth this can also contribute to drastic fluctuations in the available oxygen. The pH of the water can also be affected. An airstone, when added to the water, will help with this problem. The airstone will help by moving the surface of the aquarium water, therefore allowing gases (carbon dioxide and oxygen) to be more readily exchanged there.
The most common cause of the growth of green algae is excessive light. An aquarium located where it receives direct sunlight for a large portion of the day, or simply leaving the aquarium light on for extended periods of time are the two main causes of the problem. This type of algae is easy to control simply by decreasing the amount of light the tank receives, scraping the sides, cleaning the artificial plants and ornaments and then doing a partial water change.
There is a form of algae, called brown algae, that thrives in the opposite situation. This algae growth is caused by a lack of light. The treatment is the same as it is for green algae, except that light to the aquarium should be increased. The tricky part is knowing the fine line between too much and too little light. It can be easily learned with a little experimentation.
Some less common forms of algae could also present a problem. Blue-green algae usually occurs in aquariums where there is an excessively high pH or where there is a large amount of decaying material (like fish wastes, plants and fish food). Adjusting the pH to neutral and doing a partial water change should help. Yellow-green algae produces hair-like growths on the sides of the tank or on the ornaments, but can be treated using the same methods as discussed with green algae.
Chemicals solutions are available to control the growth of algae in the home aquarium. It is important to remember that these products are just what they say they are – controls. They will not kill the algae in the aquarium, otherwise they would also kill the fish. They will help to control the algae in a properly maintained aquarium.
The quality of the water is the single most important aspect of tropical fish keeping. Water can be a lot of things besides wet. It is necessary to monitor and maintain the environment in which you keep your fish so that they can be kept clean and clear. Water hardness, ammonias, the pH level and many other factors go into a well maintained aquarium. Cloudy water can be an indication of potential problems in the tank due to conditions that have somehow deteriorated.
Cloudy water is most commonly caused by an excess of bacteria in the water. This bacteria may not necessarily be bad or harmful to the fish, although it can decrease the available oxygen supply in the water.
New aquarium owners are frequently confronted with some form of cloudy water shortly after the tank is set up and new fish are introduced. This is usually due to the fact that the “balance” of the aquarium is disrupted by the new fish and the foods used to keep them alive. Cloudy water occurs because there are two types of bacteria at work here. One type feeds and multiplies on the excess food and fish wastes while the other feed on the first bacteria to keep it in check. In new aquariums there is a lack of the second type of bacteria; this leads to a cloudy aquarium. A partial water change of about 25% of the water will almost always take care of this problem. DO NOT clean the filter, this will destroy the “good” bacteria.
A more serious problem of cloudy water occurs in tanks that have been set up for some time. It is sometimes accompanied by an offensive odour. There could be many causes for this situation: improper water conditions, decaying food, too many fish, an increase in the aquarium temperature, an excess of fish wastes, a non-functioning filtration system, an undetected dead fish, or even a coating on the surface of the water that prevents the diffusion of gases. The proper course of action should be to check the tank thoroughly for any dead fish or an accumulation of decaying material at the bottom. Check the water condition – pH, water hardness and ammonia levels. Do a partial water change by siphoning about 25% of the water from the BOTTOM of the tank. Check to make sure the filter is functioning properly and that the temperature is at an acceptable level.
In extreme cases, chemicals can be added to the water to help alleviate the problem, but should be used with the above steps to assure success.