For those who have large aquariums, it is always more advisable to have two medium-power heaters, rather than a single high-powered heater. The recommendation is because if one breaks down, the other heater will serve until the damaged one is repaired or replaced.
An aquarium must have a heater of as many watts as liters have that tank. That is, for a tank of 200 liters of water, a heater 200 watts will be needed. Following the advice in the previous paragraph, in this example, two 100-watt heaters could be chosen.
It is also advisable to have an extra heater for spare, even if it is more modest. It will avoid major complications if we have a problem in the aquarium. It also works in case we have to improvise an aquarium for spawning or a quarantine aquarium. The heaters have a thermostat to maintain the desired temperature.
The newer ones have microchips to regulate the temperature, they are much more accurate and reliable. They have a sensor located on one of the glass sides of the aquarium, which reports the temperature of the water to an external thermostat, which turns the heater on or off as required.
Also used are foils under the fish tank that heat the water. Another interesting method is the wires located in the background, but inside. They are very reliable, although it depends on the type of substrate and the vegetation present, the possibility of their use.
© Adrián Blanco 2006 — Prohibited the total or partial reproduction of text and/or images without explicit written consent of the author. —