Before you can determine which heater is best for you, you must first gather the necessary information. Before we begin, there are two very crucial things you should be aware of.

• How Large Is The Tank That Needs The Heater? The Table Below Will Help You Figure Out How Many Liters It Is.
• How Chilly Does The Room Where The Tank Is Getting? We Need To Figure Out What The Lowest Temperature In The Room Will Ever Be. (This Is Normally Done In The Early Morning, About 5 A.M.)

How big is my tank in liters?

It is critical to understand how many liters your tank holds so that you may be precise when adding or dosing goods like as pharmaceuticals and de-chlorinators.

To get the size of your tank, multiply the width by the height by the length in cm, then divide by 1000.

Keep in mind that when calculating how much water is in the tank, it is advisable to measure to the waterline rather than the tank’s top.

A 4-foot tank, for example, may be 120cm long, 45cm broad, and 45cm high.

243000 = 120 X 45 X 45
Then divide by 1000, resulting in a tank capacity of 243 liters.

How many watts?

Wattage is a measure of power consumption, and while some heaters are more efficient than others, we can use a practical guideline of 1 watt per liter.
If your tank is 300 liters, you will need at least a 300-watt heater as a starting point, but this is not the only factor to consider.
This is where your room temperature comes into play – if you set the heater at, say, 27 degrees and the ambient room temperature drops by more than 5 degrees, the heater will struggle and be too tiny, and you should consider a larger heater.