Learning topic: Provide advice on shelter and housing
Housing fish
Setting up an aquarium
Pet fish are kept in aquarium and you’ll need to provide advice regarding important issues like size, cost and the equipment needed to set up a freshwater tank.
Size
Several factors will determine the size of the tank to be set up:
The species to be kept
· tank size
· cost
· weight and flooring capacity
· the number of fish.
The table highlights the details:
The species to be kept / · Obviously larger fish require larger tanks. Not so obvious is the need to provide extra space for highly active fish- a useful analogy is comparing a Jack Russell terrier with a Saint Bernard. The Jack Russell is much smaller but probably needs more room to move because of its active nature.· Similarly, some small fish require more room because they are highly active and 'athletic' eg many barbs.
Tank size / · It is not true that fish will only grow to the size of the tank.
· A large fish will still outgrow a tank if it is too small.
· What is more likely to happen is that the inadequate amount of room will lead to poor water quality and this, in turn, will stunt the fish's growth. This is not acceptable in terms of husbandry.
· The tank size should be such that the fish can achieve its adult size and still exhibit most of its behavioural characteristics.
· The available size within the house, veterinary practice, research facility etc will also impact on the size of tank that can be accommodated.
Cost / · Cost will determine tank size. Although the tanks themselves aren't necessarily expensive, the equipment necessary to run them increases in cost as the tank size increases. For example, the stands are usually more expensive than the tanks themselves.
Weight and flooring capacity / · It is important to remember that 1 litre of fresh water weighs approximately 1 kilogram.
· The flooring where the tank is to be placed should be considered.
· A tank 180 cm x 60cm x 60 cm holds about 640 litres of water and therefore the water content alone accounts for over 600 kgs!
· When you consider that most tank stands have relatively small legs, the pressure exerted in terms of kilograms per square centimetre can be extreme and is certainly enough to destroy some flooring.
· Any tank that is over 45 cm in height will almost always be made using 10 mm glass to accommodate for the extra pressure exerted by the water. 10 mm glass is itself heavy and adds considerably to the weight of the tank.
· The weight of gravel, rocks and any other aquarium furniture also needs to be considered.
The number of fish / · The number of fish that are kept will also determine the tank size (or, conversely, the tank size will determine how many fish can be kept).
· The surface area of the tank is the main limiting factor in this regard. The surface area dictates the exchange of oxygen between the water and air.
· Surface area is calculated by multiplying the tank width by its length. For example, a tank 180 cm long and 60 cm wide has a surface area of 10,800 square centimetres.
· For tropical fresh water aquaria, allow 26 square cms per centimetre of fish. It is important to remember that larger fish need more space in proportion to their body size.
As a general rule…
Larger tanks are more stable than smaller tanks. They are less prone to sudden changes in water temperature and water quality. The largest tank that is feasible should always be chosen.
The environment is inherently more stable in a large tank, but the size of the tank may present other problems.
Equipment needed to set up a freshwater tank
· The tank and lids.
· Polystyrene foam and stand
· Gravel or sand (bed media)
· Aqua scaping features (tank furniture) eg rocks, logs.
· Hose or siphon.
· Filter and filter medium.
· Mild disinfectant
· Water
· Water ager or conditioner (optional)
· Heater
· Thermometer
· Lights
· Power board
· Air stones or other aeration device (optional), with air hoses
· Air pump if using air stones or air powered filters
· Testing kits for water.
The tank and lids
The size of the tank has already been discussed above. It is important to realise that the limiting factor to the number of fish kept is the surface area (see above). This means that some tanks have a large water capacity but a small fish capacity- the classic example is the tall hexagonal or round tanks that are commonly sold in non-specialist pet shops. Although these tanks often hold many hundreds of litres of water they are limited in the number of fish they can house because of their relatively small surface area.
Lids are useful because:
· They prevent fish jumping out of tanks. Some fish are such powerful jumpers that extra weights are required on top of the lids eg: Arowanas.
· They prevent predation by household pets eg cats.
· They prevent contaminants from falling into the tank eg insects, cigarette ash.
· It is worth assuming that any insect in your house is likely to be contaminated with low levels of insecticide- most fish are extremely sensitive to insecticides.
Note: The lids should be cut to enable easy access to the water surface for planting, removal of dead fish etc.
Lids are almost always necessary. The areas where the lids have been shaped are called 'cut outs' and are necessary to allow for the passage of filter inlets/outlets, electrical leads, etc.
Warning!Obviously the tank needs to be handled with care- most tanks are sealed with silicone compounds that are extremely strong but they still won't cope with excessively rough handling.
TANKS SHOULD NEVER BE MOVED WITH ANY SIGNIFICANT AMOUNT OF WATER IN THEM- not only is this dangerous for the person moving them, but they are not designed to handle this sort of stress.
Polystyrene foam and stand
The stand needs to be the correct size and strength for the tank (when fully laden). It is probably safer to purchase a stand from a reputable dealer than to attempt to make one yourself. The site for the tank needs to be chosen with care as it is time consuming and stressful for the fish (and the humans!) to have to break down and set up a tank again.
When choosing the site for the tank the following should be considered:
· Try to avoid excessive direct sunlight. This encourages algal growth and in Summer can lead to overheating of the water.
· Avoid high traffic areas- fish have excellent eyesight and can be easily stressed by continual movement near tanks. This is particularly the case with some excitable species eg Angel fish. High traffic areas also increase the likelihood of the tank being knocked, damaged or of contaminants being introduced eg cigarette smoke.
· Placing a tank near a window can lead to problems with temperature maintenance. Glass is a poor insulator and heat will radiate out of windows in the Winter. If a window is unavoidable it should be one with heavy curtains or other covering.
· Placing tanks under air conditioning vents is also not a good idea.
· Avoid placing tanks near electrical equipment eg computers, audiovisual equipment. Water and electricity are a dangerous mix!
Once the site is decided upon, the stand should be placed and checked that it is sitting level. Now is the time to ensure that your flooring is not going to collapse or be damaged. The polystyrene foam is placed on the stand and the tank settled on the foam.
The foam serves to:
· Insulate the tank at the bottom to decrease heat conduction.
· 'Smooth out' any irregularities in the stand so that the tank finds it own level.
Disinfectant
The tank should also be cleaned on the inside to remove dust and any residues that may have accumulated while it has been standing in the store.
Usually water and a clean cloth is adequate.
Some people prefer to use mild disinfectant. Great care must be taken when using chemicals in relation to fish.
If a disinfectant is used it should be checked for safety information and all residues should be removed with water before the tank is filled.
If there is any doubt about the safety of the disinfectant used, do not use it.Gravel and sand
The choice of media to be used on the bottom of the tank will depend on several factors:
The species being kept may require a certain size of gravel or sand to satisfy its feeding or breeding behaviours.
If sub gravel filtration is to be used then this usually requires that gravel of a certain minimum size is used.
Preparing the gravel:
· Any gravel or sand that is used should be thoroughly washed and rinsed before being introduced to the tank.
· This should be done even if the gravel comes in a bag that is labelled 'pre-washed'!
· Gravel or sand from natural sources should be treated with caution- it may contain contaminants such as heavy metals that may not be able to be washed away. It may also harbour parasites or other pathogens.
There are many different types of gravel and sand available.
Factors to consider include whether sub gravel filtration is to be used, the fish to be kept and personal preference.
· Once the medium has been washed it should be placed in the tank. If sub gravel filtration is being used it should be placed and connected now.
· The common practice is to aim to have a bed of medium at least 8-10cm deep (in a 60cm high tank), with the depth being greatest at the back and sloping gently to the front.
The sloping is done to:
· Allow waste material to 'roll' to the front of the tank for easier detection and collection.
· Provide an optical illusion of depth.
· Allow for easier aqua-scaping- just as in garden design, the tallest objects should always be at the back.
Aqua-scaping
Once the medium is in place (with sub gravel filtration, if being used) the aquarium 'furniture' should be introduced to the tank. Furniture may be rocks, logs, plastic ornaments and other items.
Furniture is used to:
· improve the aesthetics of the tank
· provide environmental support for the fish (hiding places, breeding opportunities etc)
· break the tank up into smaller areas to satisfy the territorial needs of some fish.
Note: Any furniture should be carefully washed and cleaned. Rocks and logs in particular are likely to harbour spiders, insects and other undesirables.Logs are popularly used in tanks.
· These should be soaked for at least a few days before being placed in the tank.
· Most logs sold in Australia contain tannin- this will leach out and stain tank water brown unless it is leached out by soaking first. The tannin is not particularly harmful for the fish (in fact many fish live in water that has high tannin content in the wild) but most aquarists consider it unsightly.
· Some logs will prove refractory to soaking and still leach tannin after many weeks of soaking.
· One other problem with logs is that some of them float and this obviously makes them unsuitable for home aquaria. They can be weighted but any metallic weights should be treated with caution as they can contaminate the water.
The arrangement of the tank furniture is very much up to individual taste but some general principles include the following:
· Avoid making the tank too symmetrical. This results in an unnatural appearance and will appear 'contrived'.
· The taller pieces of furniture should be towards the back of the tank.
· Take care that the furniture doesn't interfere with the operation of equipment (heaters, filters etc).
· Take care that the furniture won't cause problems in the future with retrieval of dead fish, cleaning of the tank etc.
Larger rocks are also popular.These weigh a considerable amount and may present problems in terms of manipulating them into the tank. You should always consider your own health when attempting to move heavy objects- get help if you need it.
Some people will partially fill the tank with water before placing heavy rocks because the water then takes part of their weight, making them easier to manoeuvre.
Adding the water
The water should be added gradually. There are techniques to avoid sediment becoming mixed with the water but if the medium has been cleaned adequately this should be of minimal concern.
Water should be added to about one quarter of the tank's height and then a mark made to indicate the water level.
The tank should be left for several hours and then rechecked to ensure that the water level has not dropped.
This should be repeated until the tank is almost full. Signs of leaking include falling water level, air bubbles (especially at the joins of the sheets of glass) and unexplained water on the floor.
Chemical water 'agers' or 'conditioners'
There is some debate about whether to use chemical water 'agers' or 'conditioners'. The aim of most of these preparations is to cause harmful elements to dissipate or otherwise be eliminated from the water. They are mainly targeting:
· chlorine
· fluorine
· ammonia
· chloramines
· heavy metals