Tropical Fish

Keeping tropical fish involves a lot of time and effort and you should be sure that you are able to put this in before you get your fish.

There are many types of tropical fish that are available from pet shops in New Zealand. The best place to start is with a small community tank with guppies, angel fish, tetras and other small fish.

As tropical fish require a controlled environment, you will need the following equipment as well as a tank:

• A piece of Pinex or polystyrene to put under the tank for support

• A water heater with built-in thermostat.

• An electric air pump and about 2 metres of clear plastic hose

• A thermometer, either mercury or plastic stick-on

• An airstone

• Aquarium gravel of small clean pebbles to put at the bottom of the tank

• Fish food – talk to your local pet shop, they can tell you what is the best type of food for your fish and can also supply you with all of the above equipment

How to set up your tank

Decide on a suitable place to keep the tank, making sure that it is not in direct sunlight. Wash the tank thoroughly with clean water – no detergent please as it can kill the fish.

The tank needs to be put somewhere stable, and make sure you remember to put the Pinex or polystyrene underneath the tank. Place the thermometer in the tank where you can easily read it.

Put about 2cm of aquarium gravel or small pebbles at the bottom of the tank, connect the plastic hose to the air pump and airstone, and run the tubing down the side of the tank so that the airstone is on the bottom of the tank.

Place the heater in the tank, but make sure you do not turn the heater or air pump on yet.

You are now ready to fill your tank to about 6cm, from the top, using fresh water. Allow it to stand for a least 24 hours so that any chlorine in the water can evaporate. Remember – chlorine can kill fish, so never fill the tank straight from the tap.

Tropical fish need water temperatures of approximately 25 degrees Celsius to survive, so you can now turn the heater and air pump on and wait until the temperature has reached the correct level. This should take about the same time as it does for the chlorine in the water to evaporate.

When you bring your fish home they will probably be in water in a plastic bag, so put the whole bag into the tank for about 10 minutes to allow the temperature of the water in the bag to become the same as the water in the tank, and then tip the fish and water in.

Make sure you go to a good pet shop where the fish and water tanks are really clear or you could get sick fish.

What to feed your fish

There is lots of good fish food available and your pet shop will be able to help you choose.

To begin with, feed your fish once a day. After about a week feed them twice a day, in the morning and in the afternoon.

Give a small pinch of food to start with and leave it for 10 minutes. If it hasn’t been eaten by then, remove it. Otherwise it will pollute the water and could result in dead fish.

Cleaning your tank

The next important point to remember is to keep the tank clean. This will take you about an hour every two weeks so be sure to mark it on your calendar. Fish can’t keep their water clean themselves so you have to do it for them.

Probably the number two killer of fish is ammonia. Ammonia is what results when fish wastes, uneaten food, decaying plants, etc; are broken down. Ammonia can make the water very acidic. To prevent a build-up of ammonia and acid water, you must do partial water changes every two weeks, making sure to turn the heater off while you change the water.

The best way to change the water is to buy a glass siphon tube and hose, and siphon out about 30% of the water from the bottom. Get the tube right down into the gravel, suck on the end and let the water run down into a bucket. Work the siphon tube across the tank or bowl bottom. You will be surprised how much it picks up. Now top up the bowl with water that has stood for at least 24 hours (no chlorine).

Sometimes, if there is a bit too much light, green algae may grow on the sides of the tank. This can be carefully scraped off and siphoned away. Long-handled razor-blade scrapers can be used on glass aquariums. Green algae is harmless to fish but it does look most unattractive.

Points to note

• Do not overfeed your fish – give only one to two feeds a day, and all the food is to be eaten in 10 minutes.

• Do not overcrowd your aquarium. The pet shop where you buy your fish will advise you on how many and what kind of fish you can keep safely together. If you want large numbers of fish, you must consider getting a filtration system, and a large tank.

• Keep up the partial water changes – 30% every two weeks. Mark it on the calendar if necessary.

• If flyspray or hairspray must be used in the same room as your fish bowl or aquarium, make sure you cover the bowl first. These sprays can be fatal to fish.

• Fish can get all sorts of fungal diseases. If in doubt please consult your vet.