How Many Watts of Light Per Gallon for Your Aquarium
By Eddie Waithaka @aquariawise
quarium enthusiasts often ponder the best ways to light their tanks.
Some may think that more watts of light are always better, but this is not necessarily the case. To find the best lighting for your aquarium, you must first understand how watts of light translate to gallons of water…
Plus, with the advent of LED aquarium lights, you’ll also need to know how many lumens of light you will need per gallon of water.
So, how many watts per gallon of water is ideal for your fish tank?
Well,…
1 to 2 watts of light per gallon of water is recommended for a freshwater, fish-only aquarium or a low-light planted tank. 2 to 4 watts per gallon is best for a medium-light planted tank, and 4 watts per gallon is ideal for an aquarium with high-light plants.
0.25 to 0.5 watts of light (10 to 20 lumens) per liter of water is recommended for a freshwater, fish-only aquarium, or a low-light planted tank. 0.5 to 1 watts per gallon (20 to 40 lumens) is best for a medium-light planted tank, and 1 watt per liter (40 lumens) is ideal for an aquarium with high-light plants. About 160 lumens per gallon.
| Fish Tank Specs | Watts Per Gallon | Watts Per Liter | Lumens per Liter | |||
|---|---|---|---|---|---|---|
| Fish-only Aquarium | 1 to 2 watts of light per gallon of water | 0.25 to 0.5 watts per liter | 10 to 20 lumens | |||
| Low-light Planted Aquarium | 1 to 2 watts of light per gallon of water | 0.25 to 0.5 watts per liter | 10 to 20 lumens | |||
| Medium-light Planted Aquarium | 2 to 4 watts of light per gallon of water | 0.5 to 1 watt per liter | 20 to 40 lumens | |||
| High-light Planted Aquarium | 4 watts of light per gallon of water | 1 watt per liter | >40 lumens |
That said…
Please note that aquarium light wattage and lumens per gallon only serve as guides. Other factors, such as fish tank depth, water clarity, and the height of light from the tank, matter when considering aquarium lighting.
So, in the rest of this post, we will explore the different aquarium light insights and help you decide which one is best for your aquarium.
