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Aquarium Algae – How Light Affects Growth (and How You Can Control It)
Every aquarist has seen it: green spots on the glass, brown patches on the plants, fuzzy stuff on rocks – algae! A little is normal, but too much becomes a problem.
What many don’t realize: Lighting has a huge impact on algae growth. But also on your plants! Here’s how the right brightness, color, and even UVA light can help keep your tank in balance.
Brightness – not too much, not too little
Algae love light. Especially when the light is too strong, but your plants can’t use it properly – for example, if there aren’t enough nutrients or plants in the tank.
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Too much light + nutrients = algae bloom
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Too little light = weak plant growth, algae take over
Tip: Adjust the light to match your plants. High-end LED bars can even be dimmed via app for precise control.
Light Color – the right spectrum matters
Light has color – and this light spectrum (measured in Kelvin) affects growth.
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6500–7500 K (cool white): Like daylight – great for plants, but also for algae
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3000–4500 K (warm white): Supports plant growth, less attractive to algae
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Blue-heavy light: Can encourage types like black beard algae
Tip: A balanced spectrum with some red and warm tones helps plants thrive and keeps algae under control.
Light Duration – less is often more
Many algae issues come from too much light over too long.
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Ideal lighting time: 8–10 hours per day
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Try a “midday break”, e.g. 5 hours in the morning, 5 in the evening – this can reduce algae growth
Modern LED systems let you set all this easily with an app.
Bonus Tip: UVA Light – a smart feature in high-end LED bars
Some premium LED bars include UVA light (Ultraviolet A, around 380–400 nm). Sounds technical – but it’s useful:
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Supports more natural plant growth
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Enhances fish colors (especially in guppies, tetras, etc.)
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May reduce free-floating algae spores before they settle
UVA isn’t a magic cure, but a helpful tool when combined with good lighting, healthy plants, and balanced nutrients.
Summary: Healthy lighting = fewer algae
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Choose the right light level for your plants
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Pick a balanced light color spectrum
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Use a timer or app control
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Consider UVA light as a helpful extra feature
Check out our shop – we offer top-quality LED light bars with app control and UVA, for aquariums that shine and stay healthy!