Full-spectrum LED (default)
White + warm + cool LEDs covering 6500K spectrum. Universal: works for fish-only, low-tech planted, community tanks. Fluval Aquasky, NICREW Classic, Eheim ClassicLED. Plug-and-play, dimmable on most models.
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Aquarium Lighting
💡 Aquarium lighting
Aquarium lighting — light the tank, not the algae
Get aquarium light wrong and you get green water + black-beard algae within weeks. Get it right and a planted tank looks like a window into another world. Most tanks are running too long, too bright, with the wrong spectrum. Here's the simple ruleset for clear, healthy water.
What we'll be stocking
Light types
Plant-spec LED (high-PAR)
Higher PAR (photosynthetically active radiation) for live plants. Required for carpet plants, stem plants, demanding species. Twinstar, Chihiros, Fluval Plant 3.0. Match light output to plant difficulty: low-tech 30 PAR, high-tech 80+ PAR.
Low-light LED
For Anubias, Java fern, mosses, low-tech planted tanks. Standard hood-light is enough. Save the high-PAR units for demanding plants — too much light + no CO₂ = algae bloom.
Reef / marine LED
Higher blue spectrum (12,000–20,000K) for coral fluorescence + zooxanthellae photosynthesis. AI Hydra, Kessil, EcoTech Radion. Marine-only — overkill (and wrong spectrum) for freshwater.
Smart / app-controlled
Wifi/app dimmable units (Fluval Aquasky, Chihiros) — set sunrise/sunset curves, weather effects, schedule. Adds €30–€60 over basic LED but pays back via algae prevention + plant growth. Set + forget, mostly.
Get the photoperiod + spectrum right
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6–8 hours per day, hard cap
A wild river gets ~6 hours of useful light per day (filtered by water depth + clouds). Aquariums running 10–12 hours = algae heaven. Use a plug timer (€8) or smart light. 6h for low-tech, 8h for high-tech CO₂ planted. Never "all day".
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Spectrum (Kelvin) matters
6,500K = daylight, ideal for plants + colour rendering. 8,000K+ = colder, more blue, encourages algae in some tanks. Below 5,000K = warm/yellow, fades fish colours, doesn't support plants. Stick close to 6,500K for freshwater.
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Match wattage to tank size
Old "watts per gallon" rule is dead with LEDs. Modern guide: 0.25–0.5 W LED per litre for low-tech, 0.5–1 W LED per litre for planted, 1+ W LED for high-tech CO₂. PAR meters are the precise way; for most home tanks the manufacturer chart is fine.
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Algae siesta trick
For algae-prone tanks: 4 hours light, 4 hours dark, 4 hours light, then dark for the rest of the day. Plants tolerate it; algae need continuous light to bloom. Cheap fix that helps with persistent green-water tanks.
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Position away from window
Sun on the tank = uncontrolled extra light + heat. Algae bloom guaranteed within 2 weeks. Position aquarium 2 m+ from a sunny window, blackout-curtain side if unavoidable. Cool side of the room with stable 22–25 °C ideal.
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Replace bulbs / units when output drops
LEDs lose 20–30% intensity over 3–4 years. If your plants suddenly stop growing or algae creeps back, light fade is often the cause. Most LEDs are not user-replaceable bulbs — replace the whole unit. Old fluorescent T5 tubes lose half their output in 6 months.
📦 We're stocking up
Our aquarium lighting range goes live as we vet suppliers — we won't list anything we wouldn't use ourselves. In the meantime, our calculators, breed guides and AI vet tools below are free and don't need stock.
Frequently asked questions
How long should the aquarium light be on?
6–8 hours per day, with a plug timer or smart-LED schedule. Longer = algae bloom, especially in tanks with sun exposure or high nutrient load. The siesta method (4h on / 4h off / 4h on) helps stubborn algae cases.
Why is my tank getting green water / black algae?
Three usual suspects: (1) too long photoperiod (>8 hours), (2) ambient sunlight on the tank, (3) excess nutrients (overfeeding, no plants, dirty filter). Reduce light to 6 hours, move tank from sun, do a 30% water change, clean the filter. Persistent issues = test water for nitrate.
Do I need a special light for live plants?
Anubias, Java fern, mosses, hornwort, vallisneria — basic LED hood-light works. Carpet plants, demanding stem plants (HC, glosso, rotala), most red plants — need higher-PAR plant-spec LEDs. Start low-tech with hardy plants; upgrade lights after you've mastered the easy ones.
Are smart wifi-controlled lights worth it?
For most planted tanks, yes. €30–€60 over basic, gives sunrise/sunset curves (less stress on fish), automatic schedule, dimming for algae control. Set-and-forget for years. Skip it if your tank is fish-only with no plants — basic LED + a €8 plug timer is enough.