Aquarium temperature control is one of the most overlooked and neglected considerations when trying to keep an aquarium of healthy fish.
Fish are cold-blooded which means that they cannot control their own body temperature.
It's necessary to make the water temperature correct for the fish that you have but the biggest killer of aquarium fish is rapid temperature variations.
There are several things you should do when selecting and maintaining the right water temperature.
Below I outline several of the things that you should think about when dealing with aquarium temperature.
Research the Temperature Preferences of Your Fish Before you buy any fish at all you should make sure that they all like the water temperature that you are proposing to give them.
Fish normally tolerate a range of temperature so it should not be too difficult and it should be possible to find many species of fish which like to live in temperatures somewhere between 73 and 82°F.
Stabilise Your Tank Before You Add Any Fish It is essential that you set up the tank with plants heater filter etc.
and that the tank is 'cycling' meaning that the water conditions have stabilised before you add any fish.
When it comes to adding the fish you should float the bag that they arrived in for at least 20 min in the tank water, this will equalise the temperature of the bag water and the tank water.
You should then open the bag and gradually add some tank water to it over a period of about 30 min.
After this, immerse the bag and tip it on its side so that your new fish can gently swim into the tank.
The point is you must avoid rapid temperature changes because this will stress the fish and can cause some very nasty diseases.
In fact, rapid temperature changes are the reason for stressing fish out making them susceptible to disease, can produce fungus, the shakes or shimmies which will eventually lead to their death if left untreated.
Choose The Size Of Your Heater Carefully The heater size that you choose will depend on several things; the size of your tank, the water temperature you have chosen and the ambient temperature of the room that the tank is sitting in.
Generally speaking a 30 to 40 gallon tank should have a 100 Watt heater.
If you live in a particularly warm climate then you may be able to reduce the wattage.
Similarly if you live in a cool climate you might need to increase the wattage.
To reduce the possibility of temperature fluctuations the set temperature should be at the upper end of the 73 to 82°F range if you live in a warm climate and it should be at the lower end of the range if you live in a cool climate.
This means that the heater and thermostat are not always fighting against the ambient temperature.
Where Should The Tank Be Placed As I said temperature fluctuations are the fish killer so you should place the tank away from drafts, away from radiators, away from sunlight and away from air-conditioners.
In other words away from anything that is likely to cause a rapid change in tank temperature.
Where Should the Heater Be Placed The water is heated by convection.
Convection works by warm water heated by the heater rising to the surface, cooling and returning to the bottom of the tank.
In order to not short circuit this process the heater needs to be placed at the bottom of the tank and in a central position.
There are three main types of heater these are immersible, submersible and filter heaters.
The best kind of heater for maintaining a constant temperature is the filter heater because this has a good flow of water running past it.
It has the added advantage of being outside the aquarium and therefore is not visible.
Check the Temperature Regularly It is essential that you have a clearly visible thermometer in the tank it is also essential that you check the temperature every day preferably at different times so that you can detect any temperature variations.
It is possible to use a maximum and minimum thermometer as well which, as the name suggests, monitors the maximum and minimum temperatures reached by the water.
You might also want to consider a temperature alarm.
Conclusion So long as you are aware that it is rapid temperature changes that cause problems for your fish and you take reasonable steps to avoid these then you will have a tank full of stunning, healthy and lively fish that everyone in your home will enjoy for a long time.