How to Pick the Best Planted Aquarium Light: 11 Options Compared

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The best planted aquarium light is the one that fits your tank’s length, adds the light your plants need, and mounts without blocking the water surface. A planted tank depends more on light than a tank with only fish, so the light is a main purchase rather than an add-on. Most of the lights in this group are LED models, so the guide also explains what the listing terms mean. This guide explains how to read a listing for a planted tank, then compares 11 aquarium lights using the wattage, length, spectrum and mounting figures each listing states.

Quick answer

Measure the length of your tank first, and choose a light whose listed length covers the tank without much overhang. Check the wattage and the light output figures, because a planted tank needs more light than a tank with only fish. Look for a full-spectrum listing or a color figure in the bullets, and check how the light mounts, whether it clips to the rim, sits on a lid, or stands on the tank. The picks below show each listing’s own figures.

What a planted tank needs from a light

Plants use light to grow, and the amount they need depends on the species, the depth of the tank and the substrate you use. The listings in this group do not state plant-growth results, so the figures they give are the starting point for your decision, not a promise of healthy plants.

Look for three kinds of figure. The first is wattage, which tells you the power the light draws and gives a rough sense of its output. The second is light output in lumens, which the hygger listing states as 3,869 lumens maximum. The third is spectrum, which describes the colors the light produces. Full-spectrum listings, such as the Pawfly and SEAOURA listings, name the spectrum in the bullets, and the Pawfly listing gives specific color temperatures and wavelengths.

Tank length and coverage

The length of the light should match the length of the tank. A light that is too short leaves a dark zone at one end, and a light that is much longer than the tank adds cost and may not fit the lid. The SEAOURA listing covers a 7 to 12 inch range, the AQUANEAT and MQ listings are 12-inch lights, and the Pawfly listing is 8 inches. The MarineLand listing is for tanks up to 30 inches long, and the Blosail listing is a hood for a 24-inch framed aquarium.

Measure the tank’s length along the top rim, not the cabinet, and note the inside length of the tank if you can. A light that covers the tank from end to end gives the most even light.

Worked example: matching a light to a 12-inch tank

The Pawfly light is 4 inches shorter than the tank, so it covers about two-thirds of the length if you mount it at the center. The AQUANEAT light matches the tank’s 12-inch length, so it covers the full length. For an even light across the tank, the AQUANEAT matches the tank better, while the Pawfly suits a smaller tank or a spot where you want light in the middle.

Check the mounting too. The AQUANEAT listing names a push-button switch and a timer, while the Pawfly listing names Bluetooth control. Choose the control that suits how you run the tank.

Wattage and light output

Wattage is the number most buyers look at first, but it is not the whole story. Two lights with the same wattage can produce different light depending on the LED type and the design. The listings in this group state wattage in different fields: the SEAOURA light lists 12 watts, the MarineLand light 4.62 watts, the MQ light 2 watts, the hygger light 11 watts, and the AQQA light 18 watts.

Use wattage and output together. The hygger listing gives a light output maximum of 3,869 lumens, which is a useful figure, but the listing does not give the same figure for the other products. Compare the figures the listings state, and do not assume that a higher wattage always means more light at the plant level.

Spectrum and color

Spectrum describes the colors the light emits. Most of these lights use LEDs, which emit light when current flows through a semiconductor, and the color of an LED is set by the energy its electrons need to cross the material’s band gap. A full-spectrum light covers a wide range of wavelengths, and a color-changing light can produce several colors for display. The Pawfly listing states full spectrum with 6500 K white, 660 nm red, 525 nm green and 455 nm blue. The SEAOURA listing names full spectrum with seven single colors and cycle modes. The AQUANEAT listing names full spectrum with adjustable brightness.

The MQ listing describes 16 colors and four modes, and the GloFish listing offers four light modes including blue and magenta. These options add color for display, but the listings do not state how they affect plant growth. Choose a light for the plant light first, and use the colors as an extra.

Mounting: clip, lid, hood or table

Mounting decides where the light sits and how it affects the water surface. A clip-on light attaches to the rim, and the AQQA and SEAOURA listings describe clip-on designs. A hood or lid replaces the tank cover, and the Blosail listing is a hood with colored LEDs for a 24-inch framed tank. A table-mount light sits on a stand or a stable surface, and the MarineLand listing names a table mount.

A submersible light sits in the water, and the DaToo and hygger listings describe submersible designs. A submersible light needs careful placement, so check the mounting instructions before you add it to the tank.

Controls: timers, remotes and apps

Controls matter if you want the light on a schedule. The AQUANEAT listing includes a built-in timer with three modes: 4, 8 and 10 hours. The hygger listing describes a 24/7 mode and a natural day-to-night cycle. The MQ listing includes a 24-key remote with brightness and mode controls.

The Pawfly listing describes Bluetooth control through an app, which depends on a stable connection between your phone and the light. The DaToo listing describes a dimmer switch, and the SEAOURA listing names cycle mode.

Power and placement

Most listings in this group name a corded electric power source, so plan the outlet before you buy. Keep the cord away from the water, and use a drip loop so water runs off the cord rather than into the outlet. The listings do not describe a waterproof rating for the cord, so keep the connection above the water line.

Place the light so the glare does not shine into your eyes when you check the tank, and so the light falls on the plants rather than the glass only.

Heat, placement and water

Light from an LED fixture gives off some heat, and the housing of the light carries it away. Keep the fixture clear of vents and cords, and check that the housing does not touch the water surface if the listing does not say it is submersible. A light that sits too close to the water can cause condensation on the lid or the glass, so leave a small gap for air.

Place the light so it does not fall directly on one spot of the tank glass. A light that shines on one spot can make the tank look uneven, and it can warm the water near the glass in a small tank. Move the light a little and check the glare from the front of the tank.

Cleaning and maintenance

Clean the light and the lid once a month, or when you see a film of algae or dust on the glass. Unplug the light before you clean it, and wipe the housing with a dry or slightly damp cloth. Do not spray cleaner directly on the fixture, and keep water away from the plug and the connection.

Check the mounts, clips and cords for wear. A clip that has loosened or a cord with a cracked sheath should be replaced before the light goes back on the tank. Replace any part that is damaged, and check the manufacturer’s instructions for the right part.

Matching the light to the plants you keep

Plants differ in how much light they need, and the listings do not say which plants a light suits. Before you buy, list the plants in your tank, then research their light needs from a reliable plant guide. Low-light plants tolerate a modest light, while plants that need more light grow better under a brighter, longer-running fixture. A light that works for one plant may not suit another in the same tank, so check the light against the plant you care most about.

If you are starting a new tank, begin with a light in the middle of the range you are considering, and watch the plants for a few weeks before you change the light or the schedule. Growth is slow, so give the tank time before you judge the result. Record the timer setting and the plant changes so you can compare them later.

Setting a light schedule

A steady schedule matters more than the exact hours. Many keepers set the light to come on at the same time each day and to switch off after a fixed period. The AQUANEAT timer offers 4, 8 and 10 hour modes, and the hygger 24/7 mode can run a daily cycle. Choose a schedule and keep it, rather than changing the hours each week.

Use the timer to avoid leaving the light on all day. A light left on for long periods can encourage algae on the glass and the decor, which is hard to remove once it takes hold. Check the glass each week, and adjust the hours if algae appears.

Mistakes to avoid

Buying by price or wattage alone. A planted tank needs a light that fits the tank length and mounts correctly. Check the length and mounting first.

Choosing a light that is too short. A short light leaves a dark end, and plants at that end may grow poorly.

Ignoring the mounting. A hood needs a lid that fits, and a clip-on light needs a rim of the right thickness. Check the mounting before you buy.

Assuming color means growth. Colors add display value, but the listings do not state a plant-growth effect for the colors.

Skipping the outlet plan. A corded light needs an outlet within reach of the tank and a cord that does not sit in the water.

FAQ

How long should a planted tank light be?

Match the light to the tank length. The listings in this group range from 8 inches to 30 inches.

Is a higher wattage always better for plants?

Not always. Wattage is one figure, and the listings state it in different fields. Compare wattage with light output, spectrum and mounting, and check the light at the plant level if you can.

Do I need a full-spectrum light?

A full-spectrum listing names a wide range of colors. The listings do not state a plant-growth result for full spectrum, so treat it as one factor among several.

Can I use a clip-on light on a lid?

Check the mounting. A clip-on light attaches to the rim, while a hood replaces the lid. Confirm that the light fits your tank’s rim or lid before you buy.

Do I need a timer?

A timer helps you keep a steady light schedule. The AQUANEAT listing includes a timer, and the hygger listing describes a 24/7 mode.

Is a submersible light safe in the tank?

The listings for submersible lights describe them as underwater designs. Follow the maker’s instructions for placement and power, and keep the connection above the water line.

Bottom line

For most planted tanks, the right light is the one whose listed length matches the tank, whose wattage and light output suit the plants you keep, and whose mounting fits your lid or rim. Use the eleven picks above to compare the listed figures, and confirm the length and mounting on the product page before you order. For related guides, see the light spectrum guide for aquarium plants, the Fluval Bluetooth light guide, and the auto on-off light guide.

Sources

• Light-emitting diode (Wikipedia): an LED emits light when current flows through a semiconductor, and the color is set by the energy required for electrons to cross the band gap
• Product figures: the wattage, length and mounting of each pick, as shown on its card