The best grow light is the one that fits your plant area, mounting options and available daylight. A bulb can work well over one or two plants, while a long shelf or a compact grow area needs a different shape and output.

This guide compares three exact grow lights available to buyers: a simple E27 bulb, a 60cm shelf light and a stronger dimmable panel. The specifications come from published manufacturer information; no hands-on testing is claimed.

Quick Answer

• Choose the SANSI BR30 36W if you want a focused grow bulb for one or two plants and already have a suitable open E27 lamp.
• Choose the Spider Farmer SF300 33W if you need a long, low-power light above a roughly 60cm herb, foliage or seedling shelf.
• Choose the Mars Hydro TS600 100W if you have secure overhead mounting and need a dimmable panel for a compact higher-light growing area.

None is best for every room or plant. Measure first, compare actual power rather than model-name wattage, and do not treat a tent coverage claim as a guarantee for an open room.

Do This First

Before buying, measure and record:

1. the width and depth of the plant area;
2. the distance available above the tallest plant;
3. whether the light can hang securely or must fit an existing lamp;
4. how much useful daylight already reaches the leaves;
5. the number and type of plants;
6. whether a built-in dimmer matters and whether you will use a separate timer;
7. the nearest plug location and a dry, tidy cable route.

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Best Grow Lights for Indoor Gardening at a Glance

Mars Hydro lists the TS600 at 382 × 299 × 43mm on its EU product page. Check the dimensions on the current UK listing before ordering, as product revisions can vary.

Coverage is a manufacturer claim, not a promise that every leaf receives the same intensity. Distance, optics, reflective walls, plant height and surrounding daylight all change the result.

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1. SANSI BR30 36W LED Grow Light Bulb — Best Simple Bulb for One or Two Plants

Why It Made the List

The SANSI BR30 is the most straightforward option here: a 36W grow bulb offered in a UK E27 version. It suits a small area where a bar or panel would be awkward, provided you already have a stable, open light fitting that can point the bulb at the plants.

SANSI publishes total photon output and a PPFD reading at a stated distance. That is more useful than a vague “400W” comparison, but it still does not define an evenly lit footprint.

Key Specifications

• Actual power: 36W. The advertised “400W equivalent” is not its electrical draw.
• UK fitting and voltage: UK E27 option; the manufacturer lists 220V for EU/UK.
• Dimensions: Not stated by the manufacturer.
• Weight: 0.836 lb, about 0.38kg.
• Spectrum: 4000K, described as 400–780nm full spectrum.
• Published output: PPF 65.6 µmol/s; PPFD 265.58 µmol/m²/s at 1 foot.
• Published coverage: Not stated by the manufacturer.
• Beam angle: 60°.
• Dimming: No; the manufacturer says not to use it in a dimmable fitting.
• Timer: No.
• Mounting: A suitable open E27 lamp or holder supplied by the buyer.
• Recommended height: 30–50cm from the plants, according to the manufacturer.
• Warranty: Two years for the EU/UK version.

What It Suits

This bulb is better suited to one larger houseplant or a tight group of one or two pots than a long seedling tray. Its actual electrical draw is 36W, regardless of the “400W equivalent” wording used in some product marketing.

Use the published 30–50cm range as product-specific guidance, then watch the plants and check the fitting remains stable and ventilated. For a fuller positioning process, use the grow-light placement guide.

Limitations

• The bulb does not include a stand, shade or timer.
• The manufacturer does not state fixture dimensions or a coverage footprint.
• It is not dimmable.
• The bulb needs open space for cooling and must not be used in a totally enclosed fitting.
• Its directional beam is a poor match for a long shelf or broad tray.

Who Should Buy It

Choose it if you have one or two plants, a suitable open E27 fitting and enough clearance to keep the bulb securely aimed within the manufacturer’s distance guidance.

Who Should Skip It

Skip it if you need even light across a shelf, do not already have a stable E27 lamp, need built-in controls, or can only use an enclosed or shallow fitting.

Read the SANSI BR30 36W manufacturer specifications. 

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2. Spider Farmer SF300 33W LED Grow Light — Best for a 60cm Herb or Seedling Shelf

Why It Made the List

The SF300 is a 60cm-long bar rather than a square panel. That makes it a more natural match for a row of herbs, compact foliage plants or seedlings on a shelf. At UK voltage, its published draw is about 33.5W.

The manufacturer supplies exact dimensions, total output, spectrum and a hanging kit. Its 60 × 76cm coverage claim is useful for initial planning, although the product page does not place that number beside a hanging height or PPFD map.

Key Specifications

• Actual power: 33.47W ±5% at AC240V.
• Input: AC100–240V, 50–60Hz.
• Dimensions: 600 × 150 × 35.4mm.
• Spectrum: 660–665nm, 730–740nm, 2800–3000K and 4800–5000K.
• Published output: 74.92 µmol/s total output; PPE 2.3 µmol/J.
• Published coverage: 60 × 76cm.
• Dimming: Not stated by the manufacturer.
• Timer: No built-in timer stated.
• Mounting: Two hanging kits included; 130cm power cord.
• Recommended height: Not stated by the manufacturer on the product page.
• Fan behaviour: Fanless, with a published 0dB specification.
• Warranty: Five-year after-sales service through the UK repair centre.

What It Suits

The narrow footprint suits plants arranged in a row: a herb shelf, a small seedling run or several foliage plants with a similar canopy height. Its low-profile shape may also work under a shelf where a bulb would spread light less evenly.

Measure the full 600mm fixture length before ordering. Treat the coverage figure as a starting claim and use the model’s manual plus plant response to set height; the product page does not publish the test height beside that footprint.

Limitations

• It needs secure overhead hanging rather than a desk or clip mount.
• There is no stated dimmer or built-in timer.
• Its long, narrow shape is not ideal for a deep square plant area.
• The coverage claim lacks a visible test height and measurement map.
• The official page states compatible voltage but does not identify the supplied plug shape in its visible specification table.

Who Should Buy It

Choose it for a shelf close to 60cm wide where you can hang a light directly over a row of herbs, seedlings or similarly sized foliage plants.

Who Should Skip It

Skip it if your shelf is shorter than the fixture, hanging is not possible, you want a built-in dimmer, or you need a stronger square footprint for several high-light plants.

Read the Spider Farmer SF300 manufacturer specifications or check the exact SF300-UK model on Amazon.

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3. Mars Hydro TS600 100W Dimmable LED Grow Light — Best for a Compact Higher-Light Area

Why It Made the List

The TS600 is a 100W-class square panel with a dimmer. It is the stronger option in this shortlist for a compact growing area where a bulb or 33W bar would be a poor physical or output match.

At UK voltage, Mars Hydro publishes a draw of 99W. The model name includes “600”, but it is not a 600W fixture. The manufacturer publishes 190 µmol/s PPF and separates vegetative coverage from the smaller flowering footprint.

Key Specifications

• Actual power: 99W at AC240V; sold as a 100W-class fixture.
• Input: 220–240V for the UK version; the manufacturer tells buyers to verify voltage before purchase.
• Dimensions: 382 × 299 × 43mm on the manufacturer’s EU TS600 page; confirm the UK 2026 version before ordering.
• Spectrum: Full spectrum. The exact Amazon UK listing gives 730–740nm red/IR, 3200–4200K and 5200–6800K.
• Published output: PPF 190 µmol/s; PPE 2.0 µmol/J.
• Published coverage: 60 × 60cm for vegetative growth and 45 × 45cm for flowering.
• Dimming: Yes, on the 2026 updated version.
• Timer: No built-in timer stated.
• Mounting: Hanging panel; supplied hardware is not clearly listed in the UK product copy.
• Recommended height: Not stated in the visible UK specification; follow the exact version’s manual.
• Fan behaviour: Fanless aluminium heat sink.
• Warranty: Two-year limited warranty for the TS600 under the Mars Hydro UK policy.

What It Suits

This panel makes more sense than the bulb or bar when you have a compact square plant area, secure overhead mounting and plants that need a stronger setup. The dimmer gives useful adjustment when plants are young, clearance is limited or the fixture cannot be raised immediately.

The published footprint is framed around grow-tent use. Reflective tent walls return light that an open room loses, so do not assume the same intensity across a 60 × 60cm table in a living room.

Limitations

• It draws roughly three times as much power as the SF300.
• It needs secure hanging, more clearance and a sensible way to manage glare.
• There is no built-in timer stated.
• The published coverage is tent-oriented.
• The UK page does not clearly state plug shape, hanging-kit contents or a version-specific distance chart in its visible copy.

Who Should Buy It

Choose it if you need a stronger dimmable panel for a compact square area and can provide safe overhead mounting, ventilation and enough clearance for plant growth.

Who Should Skip It

Skip it for one shade-tolerant plant, a shallow living-room shelf, a setup without secure suspension, or any space where a bright overhead panel would create unacceptable glare.

Read the Mars Hydro TS600 manufacturer specifications or check the exact upgraded dimmable TS600 on Amazon.

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Do You Actually Need a Grow Light?

Do not buy one simply because a plant grows slowly. A grow light may be unnecessary when:

• the plant already receives enough natural light for its needs;
• moving it nearer a suitable window solves the problem safely;
• yellowing or poor growth is caused by wet compost, damaged roots, pests or temperature rather than light;
• a tiny area is already covered by a suitable lamp;
• you cannot mount the proposed fixture securely or route its cable away from water.

The indoor plant grow-light guide explains when supplementary light is likely to help and what it cannot fix.

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Which Grow Light Type Fits Your Setup?

One or Two Houseplants

Look for a compact fixture, manageable actual power and a stable way to aim it. An E27 grow bulb can be the simplest route when you already own a suitable open lamp.

Herb or Seedling Shelf

Prioritise even horizontal coverage, a fixture that fits the shelf, secure mounting and easy height adjustment. A timer is useful for consistency, but it does not compensate for weak output or poor positioning.

Several High-Light Plants

Look for a larger published footprint, meaningful PPF or PPFD data, dimming and secure suspension. Check whether the manufacturer’s coverage is for vegetative growth, flowering or both.

Open Room vs Grow Tent

Reflective tent walls change light distribution. A footprint measured or recommended in a tent may perform differently above an open table or living-room plant group. Use the manufacturer’s chart for the exact model and adjust with the grow-light placement guide.

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What to Look for When Buying an Indoor Grow Light

Actual Power Draw

Read the electrical input in watts. A name such as “TS600” or wording such as “400W equivalent” does not mean the light consumes 600W or 400W. The three products here actually draw about 33–99W.

Coverage

Match the published footprint to the width and depth of your plants, then check how that footprint was measured. Coverage without a height or PPFD map is only a rough planning claim.

PPF and PPFD Data

PPF describes the total stream of plant-usable photons leaving a light. PPFD describes how many reach a square metre each second at a particular point or area. A single centre PPFD reading does not prove even coverage.

A brand that publishes output data makes comparison easier, but missing data alone does not prove that another light performs badly.

Spectrum

Full-spectrum white grow lights are practical in many homes because they support plant growth without a strong purple cast. Spectrum is only one part of the decision: intensity, distance, duration and coverage still matter.

Dimming

Dimming is useful when a panel is powerful for young plants, the hanging distance is limited or the canopy changes. It is not essential for every small bulb or fixed shelf light.

Timer

A timer makes a consistent daily routine easier. It does not measure plant needs or automatically choose the right intensity and distance.

Mounting and Clearance

Check hanging points, shelf height, the plant’s expected growth, the fixture’s weight, cable length and the route to a plug. Leave the clearance required by the manufacturer.

Heat and Airflow

LED grow lights still produce heat. Fanless designs use their body or heat sink to release it, so do not cover the fixture or block cooling space. Follow the manufacturer’s limits for enclosed fittings and operating conditions.

Safety

Use correctly rated equipment, secure the light with the manufacturer’s mounting method, keep plugs and connections away from water, and inspect cables before use. Do not improvise a suspension system that cannot safely support the fixture.

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Common Grow-Light Buying Mistakes

• Choosing by a “1000W”-style name instead of actual power draw.
• Buying a fixture wider than the shelf.
• Assuming a coverage claim applies at every height and in every room.
• Buying a strong panel for one shade-tolerant plant.
• Ignoring mounting clearance and the plant’s future height.
• Placing a powerful light too close without following its manual.
• Assuming a timer knows how much light the plant needs.
• Expecting light to solve root damage, poor drainage or watering problems.
• Buying before checking whether natural daylight is already sufficient.

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FAQs About Buying Grow Lights

What wattage grow light do I need for indoor plants?

There is no useful universal wattage. Start with plant type, growing-area dimensions, daylight and mounting distance, then compare the manufacturer’s actual draw, footprint and output data for the exact model.

Are LED grow lights expensive to run?

Running cost depends on actual watts, daily hours and your electricity tariff. Multiply the wattage by the hours used, convert watt-hours to kilowatt-hours, then apply your tariff. Do not use an “equivalent” wattage in that calculation.

How far should a grow light be from plants?

Use the exact manufacturer’s height or PPFD chart because optics and output differ. If no distance is published, ask the manufacturer rather than applying a generic number. The placement guide explains how to adjust a setup from plant response.

Do I need a timer?

No, but a timer can make a consistent routine easier. It is a convenience feature, not a substitute for choosing the correct output, distance and duration.

Can a normal LED bulb grow plants?

A bright household bulb may provide some supplementary light, but its output, beam and spectrum may not be published for plant use. A horticultural bulb with relevant measurements makes the setup easier to assess.

Is a stronger grow light always better?

No. Excess output can waste electricity, create glare, increase heat and stress plants when distance is limited. Choose enough usable light for the measured area and plant needs, with dimming or height adjustment where useful.

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Final Thoughts

Choose by the space you actually have. The SANSI bulb is the simple focused option, the SF300 is shaped for a shelf, and the TS600 is the stronger dimmable panel for a compact square area. Before ordering, check actual power, fixture dimensions, mounting, published output, coverage context and the exact UK electrical version.

Good manufacturer data narrows the choice, but it does not replace measuring your setup or observing the plant after installation.

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Related Articles

• Indoor Plant Grow Light Guide
• Grow Light Placement