How to Set Light Intensity?

[veljko]

Hello.

I need some help with light settings for my 3g, fully planted betta tank. I have recently updated the tank with CO2 and some red plants and HC carpet. I have just received the C2 RGB light. My tank looks great with it but as a beginner, I have no idea what to set it to. I am very cautious about algae.

Tank photo attached.

HC carpet that has already carpeted the whole substrate.
Other plants are:

java fern
a few anubias nana petite
a few narrow leaf swords
some guppy grass
Some moss

Reds:

Rotala H'ra
Ludwigia Repens
Ludwigia Super red mini
Alternanthera Rosanervig
Eriocaulon Quinquangulare
red root floaters

Thank you for any advice.

 

[Administrator]

Hello.

I need some help with light settings for my 3g, fully planted betta tank. I have recently updated the tank with CO2 and some red plants and HC carpet. I have just received the C2 RGB light. My tank looks great with it but as a beginner, I have no idea what to set it to. I am very cautious about algae.

Tank photo attached.

HC carpet that has already carpeted the whole substrate.
Other plants are:

java fern
a few anubias nana petite
a few narrow leaf swords
some guppy grass
Some moss

Reds:

Rotala H'ra
Ludwigia Repens
Ludwigia Super red mini
Alternanthera Rosanervig
Eriocaulon Quinquangulare
red root floaters

Thank you for any advice.

You can set around 60%, add 5% each week for the growth, use Preset mode like Red, Green, Buce...Slightly adjust by +- 5%-10% when it get lush.

 

[Kms520]

Hello admin,
I am using a WRGB2 Slim 45,What light setting should I start with (20%?) and how much of an increase per week till maturation?( What is the max intensity do you recommend for maturation)
Tank dimension: 50x32x34 cm
New tank with CO2.
Plants: Blyxa Japonica, Rotala SP Green, Alternanthera Reineckii Mini, Rotala Blood Red, Cryptocoryne Parva, Bucephalandra Godzilla (Kedagang Red),Hygrophila Pinnatifida ,Vallisneria Spiralis ,Vesicularia ferriei 'Weeping', Bucephalandra Brownie Blue.

Also, by % do you mean for example 20% means 20 in each of red, green, blue? Do I have to adjust the white and Kelvin or is it adjusted automatically?

 

[Administrator]

Hello admin,
I am using a WRGB2 Slim 45,What light setting should I start with (20%?) and how much of an increase per week till maturation?( What is the max intensity do you recommend for maturation)
Tank dimension: 50x32x34 cm
New tank with CO2.
Plants: Blyxa Japonica, Rotala SP Green, Alternanthera Reineckii Mini, Rotala Blood Red, Cryptocoryne Parva, Bucephalandra Godzilla (Kedagang Red),Hygrophila Pinnatifida ,Vallisneria Spiralis ,Vesicularia ferriei 'Weeping', Bucephalandra Brownie Blue.

Also, by % do you mean for example 20% means 20 in each of red, green, blue? Do I have to adjust the white and Kelvin or is it adjusted automatically?

For a tank 50x32x34cm with light WRGB2 Slim 45 it's suitable.
Start at around 20% is okay, add about 5% each week for growth, you can end when it's the first time to trim then replant.
20% and 5% are not an exact number for each color, you can slightly adjust as your tank situation, eg. more red plants red percentage more.
As for the Overall brightness and Kelvin, if you set well the RGB channels, the 2 will be set automatically, but they don't show the exact value just show default 3000K(Just ignore the showing issue).

 

[Kms520]

For a tank 50x32x34cm with light WRGB2 Slim 45 it's suitable.
Start at around 20% is okay, add about 5% each week for growth, you can end when it's the first time to trim then replant.
20% and 5% are not an exact number for each color, you can slightly adjust as your tank situation, eg. more red plants red percentage more.
As for the Overall brightness and Kelvin, if you set well the RGB channels, the 2 will be set automatically, but they don't show the exact value just show default 3000K(Just ignore the showing issue).

Am still not too sure about the % part. Can I assume that if the max intensity is 35w. Then 20% is 7w?

 

[Administrator]

Am still not too sure about the % part. Can I assume that if the max intensity is 35w. Then 20% is 7w?

If there is a power usage ring in the app Manual mode you can check.

 

[Kms520]

If there is a power usage ring in the app Manual mode you can check.

Like this? How much blue do I actually put?

 

[Administrator]

Like this? How much blue do I actually put?

Red, Green, Blue are around 20%, you can slightly adjust by +- 5%.

 

[Sefo]

Hi,

I am planning to set up a hightech planted tank with a tube CO2 system, measuring 65x40x45. I bought 60 cm chihiros wrgb II as lighting. "How to Adjust the Light Intensity?" shared by you. I have read your article and other posts in the forums, but I still have some questions about lighting, I would be glad if you could answer them.

1. You suggested that you start with 30% light intensity in the initial setup of the aquarium and then increase it by 5% weekly. But I couldn't figure out how to set this light percentage to 30% with the application. Should I set the red, green and blue channels in the settings section of the application to 30%, or should I adjust these three channels with appropriate percentages and set the white channel under these three channels to 30%?

2. How many hours should the lighting duration be initially and how should it be increased later?

 

[Administrator]

Hi,

I am planning to set up a hightech planted tank with a tube CO2 system, measuring 65x40x45. I bought 60 cm chihiros wrgb II as lighting. "How to Adjust the Light Intensity?" shared by you. I have read your article and other posts in the forums, but I still have some questions about lighting, I would be glad if you could answer them.

1. You suggested that you start with 30% light intensity in the initial setup of the aquarium and then increase it by 5% weekly. But I couldn't figure out how to set this light percentage to 30% with the application. Should I set the red, green and blue channels in the settings section of the application to 30%, or should I adjust these three channels with appropriate percentages and set the white channel under these three channels to 30%?

2. How many hours should the lighting duration be initially and how should it be increased later?

1. Either set the RGB or Overall Brightness and Kelvin, they are relevant.
Set RGB around 30% you can slightly adjust the percentage, eg. Red 30%, Green 28%, Blue 25%.
2. 6-8h, you can slightly adjust according to your tank situation.

 

[cubamatyas]

Hello admin,

I’m looking for advice on setting the right light intensity for my planted aquarium. Here are some details about my setup:

• Tank is 60 days old.

• Tank size: 144 liters (120x40x30cm - shallow)

• Lighting: Chihiros WRGB II SLIM (90W), positioned 15cm above the water surface, currently set at 40%.

• Lighting schedule: 7 hours daily, with a ramp-up and ramp-down period (30min each)

• Plants: Densely planted with a variety of species.

• Substrate: ADA Amazonia Ver. 2.

• CO₂ injection: A lot, using a ceramic diffuser.

• Fertilization: Comprehensive liquid fertilizer (macro and micro nutrients), dosed 3-4 times weekly.

I’ve reduced the light intensity from 50% to 40% to prevent algae growth (green hair algae and brown algae mostly), but I’m unsure if the current setting is optimal for plant growth. Some plants show signs of yellowing or fading..

How do you determine the right balance of light intensity for a densely planted shallow tank?

Any tips or recommendations would be greatly appreciated!

Thank you!

 

[Administrator]

Hello admin,

I’m looking for advice on setting the right light intensity for my planted aquarium. Here are some details about my setup:

• Tank is 60 days old.

• Tank size: 144 liters (120x40x30cm - shallow)

• Lighting: Chihiros WRGB II SLIM (90W), positioned 15cm above the water surface, currently set at 40%.

• Lighting schedule: 7 hours daily, with a ramp-up and ramp-down period (30min each)

• Plants: Densely planted with a variety of species.

• Substrate: ADA Amazonia Ver. 2.

• CO₂ injection: A lot, using a ceramic diffuser.

• Fertilization: Comprehensive liquid fertilizer (macro and micro nutrients), dosed 3-4 times weekly.

I’ve reduced the light intensity from 50% to 40% to prevent algae growth (green hair algae and brown algae mostly), but I’m unsure if the current setting is optimal for plant growth. Some plants show signs of yellowing or fading..

How do you determine the right balance of light intensity for a densely planted shallow tank?

Any tips or recommendations would be greatly appreciated!

Thank you!

View attachment 1265

Yellowing or fading leaves, this could be a nutrient deficiency, insufficient light, or CO₂ issues. Since your tank has CO₂ injection and regular fertilization, it's likely due to light intensity or a local nutrient imbalance. You can gradually increase light intensity back to 50%, or add Nitrogen or Iron.

If algae persists, reduce the photoperiod to 6h temporarily. Increase water changes or add algae-eating species like shrimps.

You can maintain 40% intensity for another 1–2 weeks to observe plant and algae responses. Gradually increase intensity by 5–10% weekly, stopping at 50–60% or when plants show improvement without exacerbating algae growth.

 

[Nataku]

Hello,

I need some advice on my light settings, my tank tends to produce filamentous algae not much but nasty
Here are some Information
60P Tank (60x30x36)
Chihiros WRGB II 10th Edition Settings in Screenshot below
Fertilizer Tropica Specialised Nutrition + Premium Nutrition 4ml each per week
Tetra 800 Plus Filtersystem
CO2 20-25 mg/l
Soil and gravel mixed with a layer of Volcano Mineral below

 

[Administrator]

Hello,

I need some advice on my light settings, my tank tends to produce filamentous algae not much but nasty
Here are some Information
60P Tank (60x30x36)
Chihiros WRGB II 10th Edition Settings in Screenshot below
Fertilizer Tropica Specialised Nutrition + Premium Nutrition 4ml each per week
Tetra 800 Plus Filtersystem
CO2 20-25 mg/l
Soil and gravel mixed with a layer of Volcano Mineral below

There are 5 suggestions according to your cussrent setup:
1. Light Settings
- Reduce Light Duration: Lower it to 6–8 hours/day(not 10h) to disrupt algae growth.
- Fine-Tune Intensity: Try reducing your red, green, and blue settings by 10–20% (e.g., Red 40%, Green 35%, Blue 40%) for a few weeks and observe changes. Algae often thrive in excess blue and red light.
2. Fertilizer Regimen
- Dose Tropica Specialised Nutrition daily (split 4ml across 7 days).
- Reduce or temporarily stop Premium Nutrition unless deficiencies in iron/micros are visible (e.g., pale leaves or slow growth).
3. CO2 Levels
- Verify that CO2 starts 1–2 hours before lights turn on and switches off 1 hour before lights go off.
4. Substrate and Organics
- Vacuum the substrate lightly during water changes to remove organic buildup. Avoid disturbing the Volcano Mineral layer.
- Perform weekly water changes (30–50%) to dilute excess nutrients and organics.
5. Other Strategies
- Add shrimps.
- Use an Algae Scraper: Physically remove visible filamentous algae during regular maintenance to reduce its spread.

 

[Nataku]

Ty for your insights! I will try out the different options