Explanation of [light] required for aquatic plants

In this article, I will explain the “light” necessary for aquatic plants.

Now, the lights of each manufacturer are excellent, so if there is a light that fits the size of the tank, it has become an era when aquatic plants grow beautifully.

However, there are various lights, so you can’t decide which one to choose?

Here are some helpful tips for choosing your lights.

  • Understanding the light specs
  • Necessary amount of light
  • Appropriate lighting time

After reading this article, you will be able to choose good lighting.
And you can know the appropriate light intensity and lighting time.

It is easy to understand for beginners, so please read it.

“Aquatic plants” and “Light”

Aquatic plants live by photosynthesis. So light is like a “meal”.

Light is the most important of all the equipment needed for aquatic plants.

Because, without fertilizer and CO2, aquatic plants do not die immediately, but without light, they die quickly.

But handling is easy!

If you make a mistake in fertilizer and CO2, it will become meaningless or rather counterproductive. However, the light is OK if you turn it on.

Technology and knowledge are not necessary.


Anyone with the money can get the same environment!

Understanding the light specs

When you choose lighting, you will probably choose to look at the manufacturer’s site or product package, but it is difficult to understand because there are not many words you can see.

Since there are only 4 important, let’s remember quickly.

  1. lumen (symbol: lm)
  2. nanometre (symbol: nm)
  3. color temperature (symbol: K)
  4. color rendering (symbol: Ra)

The most important is the lm!

If you use white light, you don’t have to worry about nm.

K and Ra are the color of the light. It looks different.

With regard to color rendering, all of the recent lights are quite high, so don’t worry too much.

K will vary greatly in appearance. If possible, it is better to choose what you are actually using in planttank.

1 lumen

In short, it means “amount of light”.
In the era of fluorescent lamps and metahalide lamps, it was based on W.

However, in the LED era, the amount of light for W changes frequently, so W cannot be fully explained.

So now I use lm to show the brightness.

2 nanometre

There is no need to think hard. There is no problem with the white light!

Please see Wikipedia for more information.

3 color temperature

Color temperature is the numerical value of the color of light.
The visual color changes depending on the light, so please check the actual thing if possible.
The lower the value, the warmer the color, and the higher the color, the colder.

4 color rendering

Ra100 is the state that reproduces the color in the same way as sunlight. Therefore, the Ra property is higher as the value is closer to 100.

By the way, white fluorescent tubes for general household use are about Ra60.

Recently released lights have a high Ra so you don’t have to worry too much.

Points when choosing a light

  • Check if lm is enough
  • Check K to see if it is your favorite color

only this!


It’s much easier than fertilizer, CO2, and water quality.

The Light intensity table by tank size

SizeEasy plantsAquascaping

Please look at this table when looking for lights.
“lm” is roughly written on the light box.
If you have trouble, ask your sales clerk!

If one light is not enough, use multiple units to secure the required lm.

If no CO2 is added, select the light referring to the “Easy plants” column.

The Appropriate lighting time

(5 hours) 8 hours to 10 hours (12 hours)

* () Is the lower and upper limit. It’s just a guide, so you can go around

“8 hours for beginners”
“10 hours for advanced users”

It would be good to use as a guide.

Aquatic plants grow better if the light is turned on for a long time. Instead, the amount of algae is increased. The opposite is true when the lamp is lit for a short time.

The Time zone

“Turn on at a fixed time every day”

Aquatic plants also have a function like a body clock. If the lighting time shifts from day to day, such as “Today from morning to night” or “Tomorrow from night to dawn”, it will not grow beautifully.

If the lighting time is constant every day, it is okay in the morning, afternoon, daytime or nighttime.

For example…

  • 8: 00-16:00 Lighting for 8 hours
  • 20:00-6: 00 Lighting for 10 hours

In this way, it is better to light up when you look at the tank.

If sunlight enters the tank when the light is not on, the aquatic plants may react and grow. In such cases, the leaves may become strange or the redness may fade. If you have an tank in the sun, you should turn it on in the daytime.

The summary

When choosing a light, pay attention to “lm”.
If you can clear the number of lms that fits the size of the tank, you can choose the light you like.

If you are an advanced user, please try to turn it on for 12 hours.
Aquatic plants grow faster. In addition, the color will improve, so you can make a more beautiful aquascape!


Thisl tank is 12 hours turn light on!

“IAPLC2018” making-of tank[IAPLC2018] Making of Tank vo1 theme and foundation makingFive Elements“Five elements” required for aquatic plants