What is the Best Temperature?
So you have setup your tank, filled it with water and the gravel is in place. Now you need to set your freshwater aquarium temperature with the heater and thermostat. What temperature should that be? The answer is that most freshwater aquariums do best between 73 and 82 degrees Fahrenheit (23 to 28 Celsius). Depending on whether you live in Alaska or LA will dictate the best freshwater aquarium temperature. This is because you want to reduce freshwater aquarium temperature changes to a minimum. So if you live in a warm climate you would want to set the thermostat at about 80 degrees Fahrenheit on the other hand in a cooler climate 75 degrees Fahrenheit would be best. This means that the impact of ambient temperature changes will be less dramatic on the freshwater aquarium temperature.
You should be aware that a higher water temperature reduces the water’s oxygen holding capacity and so greater aeration is required. It is worth saying that when comparing acrylic with glass an acrylic tank is the better insulator and therefore less prone to temperature fluctuations, a tight fitting lid also helps.
Generally speaking it is sudden temperature changes that kill fish rather than the actual temperature you set. Sudden changes in less than 24 hours are very stressful to the fish and if it does not kill them it is likely to put them in a poor state of health and make them susceptible to disease. Sudden freshwater aquarium temperature changes usually bring on the ‘shakes’ or ‘shimmies’, ‘Ichthyophthirius’ (ick), fungus or a general decline downhill.
What Size Heater?
The required heater size (in watts) will depend upon how many gallons of water that needs to be heated and the temperature difference between the room and the water. As a general rule you need 2 watts for raising each gallon of water 5 degrees above surrounding temperature. Large tanks with high temperature differentials may need two heaters. In such cases they should be put at each end of the tank.
You should not have a larger wattage heater than as calculated above. There are two reasons for this; firstly, you do not want the effect of the heater as it cycles with the thermostat to cause a rapid rise in temperature of the water and secondly, if the thermostat should fail you do not want the fish to fry.
What kinds of heaters are there?
There are three kinds of heater, all work well.
1. Immersible heaters. These are the most common mainly because they are easily found and inexpensive. They hang onto the back or side of the aquarium, dangling into the water. Above the water level there is a temperature control knob. Their disadvantage is that some people consider them to be an eyesore and prefer the heater to be hidden from view.
2. Submersible heaters. As the name implies these can be completely submerged in the aquarium. Their biggest advantage is that they can be easily hidden behind plants and rocks. These types of heaters are more reliable and can easily maintain a more consistent temperature in your tank. They’re easy to use and slimline so they don’t stand out in the aquarium, they cost more than the immersible variety but are not expensive.
3. Filter heaters. These are excellent at keeping a uniform freshwater aquarium temperature throughout the tank. They work by heating the water while it passes through a filter. They are more expensive than other heaters, but they are filter units as well. Being outside the aquarium you don’t see this kind of heater and it takes up no space, this is a big advantage!
Don’t Forget a Themometer!
One final word, make sure you have a good thermometer in your tank. Initially you should check that it is calibrated correctly. After that you should check the reading every day on a regular basis. The best time is to glance at it as you feed your fish. This will make you aware of any freshwater aquarium temperature troubles before they affect the health of your precious fish.
Conclusion
So there you have it. The actual freshwater aquarium temperature depends upon where you live but whatever it is it should be tightly comtrolled by your thermostat. The selected freshwater aquarium temperature is not as important as the prevention of temperature fluctuations.