Are aquarium lights the same as grow lights?
You might be wondering if there is a difference between grow lights and aquarium lights and if grow lights can be used for an aquarium, or if aquarium lights can be used to grow indoor plants or vegetables. In this article, we will explain the difference between grow lights and aquarium lights and if they are basically the same or not.
The primary distinction between aquarium lights and grow lights is that grow lights produce more lumens and have a higher wattage than aquarium lights because they are used to illuminate a larger area and from a greater height. Aquarium and grow light Kelvin ratings and spectrums can be identical, ranging from 3700 k to 10,000 k.
Color Spectrum
They are the same..
White light varies in color temperature, which is measured in units of kelvin (K). It can range from warm, 3000 k, up to daylight which is 6500 k, and up to white light with a bluish tint of about 10,000 k.
Aquarium plants and indoor plants or vegetables can be grown in this whole range of from 3000 k up to 10000 k.
It is a misconception that there is a huge difference between aquarium lights and grow lights because depending on the type of light, which can range from LED to metal halide, they all can be using the same color spectrum.
For aquarium lights light, most people prefer 6500 k because it stimulates daylight and makes the fish, as well as aquatic plants, look more natural
The exception to this will be some marine aquarium lights which have more of a bluish tint, and they range from 10000 k upwards. These lights will not be as effective in growing indoor plants or aquatic plants
Colour spectrum for aquarium and grow lights
| Aquarium lights | Grow lights |
| 3000K to 10 000K | 5,000 – 7,000K to promote vegetative growth |
| 3,500 – 4,500K to promote fruiting and flowering. |
As you can see in the table above, the color Spectrum for aquarium lights and grow lights range from 3000 k to 10000 k with different types of vegetables and fruiting and flowering grow lights requiring different color spectrums.
Light Intensity
This is where the real difference Between aquarium lights and grow lights are:
The intensity of lights is measured in PAR(or Photosynthetically Active Radiation).
Different types of plants will require a different PAR to be able to grow and thrive. You can also measure the brightness of lights in lumens, and this is normally stated on the particular light how many lumens it will emit.
Aquarium lights and grow lights will also be rated in watts which will indicate how powerful and bright the light will be.
Aquarium light output
| LED Light 12 watt | 1200 lumen |
| LED Light 15 watt | 1500 lumen |
| LED Light 23 watt | 2300 lumen |
| LED Light 23 watt | 3200 lumen |
In the above table, you can see when the Watts of aquarium light increases, the corresponding lumen output also increases. A 2-foot aquarium requires a 12-watt LED light-emitting 1,200 lumens, and a 4-foot aquarium will require a 23 watt LED light-emitting 3200 lumens. This lighting will be sufficient for aquatic plants to be grown effectively.
Most aquarium lights will only have to reach a height of 20 to 30 inches because that is how deep the aquarium will be.
Grow light output
| Grow light 600 watt | 90 000 lumen |
| Grow light 1000 watt | 130 000 lumen |
As indicated in the table above, both grow lights are much more powerful than aquarium lights ranging from 600 watts to 1000 watts and 130,000 lumens.
These lights will obviously be much too bright for an aquarium and grow vegetables and other plants in enclosed areas.
Light Spread
As mentioned in my previous points, most aquarium lights will only have a light spread of about 1 foot directly beneath them. Areas that fall outside of this but spread will not receive sufficient light for the plants to grow.
Most aquarium lights are also designed to fit on an aquarium. The LED lights are normally in a strip format, which means it is designed to light an aquarium and not a much bigger area as can be required to grow vegetables or other plants.
Get an aquarium light if:
- You have an aquarium and want to grow aquatic plants or corals, and want to be able to see and admire your aquarium and fish.
- You only want to grow one tray of seedlings or vegetables. Vegetable seedlings and other “full sun” plants require approximately 2000 to 3000 lumens per square foot of growing space (at a minimum). Therefore, if you’re cultivating a single standard tray of seedlings, a 3000 lumen grow lamp or aquarium light is sufficient.
Get a grow light if:
- You want to grow more than one tray of vegetables or seedlings or other types of plants
- You have a growing area of more than four square feet that you wish to illuminate and grow plants on.
Key takeaways:
- Aquarium lights are less powerful with less wattage and lumen output than most grow lights
- The colour spectrum of aquarium as well as grow lights can range from 3000 k to 10000 k
- Use aquarium lights if you want to light your aquarium or a very small patch of vegetables or plants
- Use a grow light if you want to grow vegetables or other plants and need to illuminate a fairly big growing area.
