Thinking of getting a fish tank?

Aquariums containing live plants and animals can be incredibly beautiful and many people find great joy in watching and caring for their tanks. Although tempting, one should never simply walk into a pet store, pick a couple of pretty fish and a small glass tank, and expect the story to end well.

Setting up a successful aquarium begins with a basic understanding of the needs of the fish. Most importantly, the water quality needs to be pristine. Fish pass waste products into the water and these waste products need to be removed regularly, otherwise the poor fish are effectively swimming in sewage. Naturally, this will make them very ill or even cause them to die.

1. Cleaning aquarium water

The aquarium water is cleaned in two ways. The first is by regular water changes where you remove some of the tank water and replace it with fresh water. Fish do not like sudden changes, so regular partial water changes are preferable to completely replacing the water when fouled.

The second method is by using a biological filter. Filters remove cloudiness and particulates from the water, but their main purpose is to break down the ammonia that the fish produce as waste into less harmful nitrate, which is used for growth by live plants and is also removed via water changes. The filter does this by providing a substrate upon which millions of good bacteria are encouraged to grow. Sponges, bio balls and other parts are placed in the filter and provide a massive surface area and suitable environment for these beneficial bacteria to proliferate. Filter bacteria break down ammonia through several steps and should be cared for as carefully as you care for your fish.

Never use chemicals to clean your filter! Rather use the tank water only to rinse it out when it becomes clogged.

2. New tank disease

There is a condition known as ‘new tank disease’. This is where you place fish into a newly established tank and all goes well for a week or two until the fish suddenly begin to die. What has happened is that you have not given the filter time to mature and fill up with bacteria. The fish have been producing waste which the filter is not able to process yet, and when that waste builds up too much, it kills the fish.

How does one prevent this? Firstly, the tank should be set up in an area with a stable temperature and away from direct sunlight, which causes algal growth. The new water should be treated with a product that removes chlorine and heavy metals, as these will kill fish and filters.

Your tank then needs to be cycled. This means that the tank must be run for a few weeks without fish to mature the filter and ensure a healthy environment. During this time, place a small amount of fish food into the tank daily (just a pinch). The fish food will break down and begin to provide ammonia for the filter bacteria to feed on. There are products that can be added to the water to speed up the process, or a handful of gravel from an established tank can be placed in the new tank to seed it with bacteria. Nevertheless, cycling takes time and patience now, but will be richly rewarded later.

Water testing kits are readily available and regular testing is recommended to ensure excellent water quality.

Choosing fish

Just like other animals, fish from different areas have different requirements and you need to decide on the type of setup you can afford before choosing fish. Many fish also do not play well with others, so compatibility needs to be taken into account.

  1. The simplest is a cold-water system, where no heater is needed. Goldfish, white cloud mountain minnows and some toothcarp, such as less fancy guppies, will do well here. Remember that no fish will do well in the long term in a fish bowl.
  2. Next is a tropical community tank. A heater is needed to keep the tank at about 26° Good beginner fish here include livebearers, tetra, gouramis, angels and many catfish.
  3. Some tropical fish need a species tank because they are predatory or aggressive. Larger cichlids and barbs fit in here.
  4. More specialised setups such as a discus, marine or invertebrate tank should not be attempted by beginner hobbyists.
  5. Remember never to buy a fish because you feel sorry for it, as it could introduce disease to your tank.
  6. Always choose bright, active fish and avoid purchasing fish from tanks where there are dead or sleepy fish, or where any fish have small white spots or fluffy growths on them.
  7. It is ideal to have a small quarantine tank set up and to keep new fish there for a few weeks to ensure they are healthy before putting them into your main tank.