LED Grow Light Size and Coverage Guide Australia
LED Grow Light Size and Coverage Guide Australia
Choosing the right LED grow light is one of the most important decisions in any indoor growing setup. The correct fixture depends on a combination of factors — not just wattage. Before selecting a light, consider:
- Growing-area dimensions — the floor area of your tent or growing space determines the minimum coverage your fixture must provide
- Crop and growth stage — propagation, vegetative growth and flowering each have different light intensity requirements
- Fixture efficiency — measured in µmol/J; a more efficient fixture delivers more usable light per watt consumed
- PPFD distribution — how evenly photosynthetic photon flux density is spread across the canopy matters as much as peak intensity
- Hanging height — the distance between the fixture and the canopy affects both coverage area and intensity
- Dimming range — a dimmable fixture allows you to reduce intensity for young plants and increase it as they mature
- Fixture shape — bar-style fixtures distribute light differently to square panel fixtures; shape affects uniformity across the canopy
- Heat management — all fixtures produce heat; the amount affects your ventilation requirements and tent temperature
- Manufacturer-rated coverage — always use the flowering coverage figure, which is smaller than the vegetative coverage area
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LED Grow Light Coverage Chart
The table below matches common growing areas to compatible LED fixtures currently stocked at Green Genius. Coverage figures are taken directly from product listings. Fixtures without a stated coverage area are not included in this table.
| Growing Area | Floor Area | Fixture Category | Compatible Products | Wattage | Stated Coverage | Dimmable | Controller Compatible |
|---|---|---|---|---|---|---|---|
| 60 × 60 cm | 0.36 m² | Compact panel | AC Infinity Ionboard S22 | 100 W | 60 × 60 cm | Yes (0–100%) | Yes — UIS / Controller 69 |
| 60 × 120 cm | 0.72 m² | Bar-style supplemental or small panel | AC Infinity Ionbeam S16 (4-bar kit) | 42 W total | 120 × 120 cm stated as primary (use as supplemental for 60 × 120 cm) | Yes (10–100%) | Yes — UIS |
| 120 × 120 cm | 1.44 m² | Mid-to-high output panel or bar array | AC Infinity Ionframe EVO6 | 500 W | 120 × 120 cm (flower) | Yes | Yes — UIS / Controller 69 Pro |
| 120 × 120 cm | 1.44 m² | High-efficiency panel | LFG 600 W LED | 600 W | 120 × 120 cm to 150 × 150 cm | Yes (0–100%) | Dimmer knob (built-in) |
| 120 × 120 cm | 1.44 m² | High-efficiency panel | LFG 720 W LED | 720 W | 120 × 120 cm to 150 × 150 cm | Yes (0–100%) | Dimmer knob (built-in) |
| 150 × 150 cm | 2.25 m² | High-output bar array | AC Infinity Ionframe EVO8 | 730 W | 150 × 150 cm (flower) | Yes | Yes — UIS / Controller 69 Pro |
| 150 × 150 cm | 2.25 m² | High-output bar array | AC Infinity Ionframe EVO10 | 1000 W | 150 × 150 cm (flower) | Yes | Yes — UIS / Controller 69 Pro |
| 120 × 150 cm to 180 × 150 cm | 1.8–2.7 m² | Bar-style | LFG 650 W Light Bar | 650 W | 150 × 120 cm to 180 × 150 cm | Yes (0–100%) | Dimmer knob (built-in) |
| 120 × 90 cm (under-canopy) | 1.08 m² | Under-canopy supplemental | LFG Under Canopy LED 120 W (×2) | 120 W per unit | 120 × 90 cm per unit | Yes (0–100%) | Built-in dimmer |
Note: The Treegers 15 W and 30 W E27 bulbs are not included in this table as no grow-tent coverage area is stated in their product listings. They are suitable for small ornamental or supplemental applications. The Ionbeam S16 is primarily a supplemental bar light; its stated 120 × 120 cm coverage applies when used as a primary light in that configuration.
Why Wattage Is Not the Same as Light Output
Two fixtures with identical wattage can deliver very different results. Understanding the following terms will help you make a better-informed decision.
Input wattage is the amount of electricity the fixture draws from the wall. It tells you the running cost but not how much usable light reaches your plants.
Photosynthetic photon flux (PPF) is the total amount of light in the photosynthetically active range (400–700 nm) produced by the fixture each second, measured in µmol/s. A higher PPF means more light is being generated, but it does not tell you how that light is distributed.
PPFD (photosynthetic photon flux density) is the amount of light actually arriving at a specific point on the canopy, measured in µmol/m²/s. This is the figure most relevant to plant growth. PPFD varies across the canopy — it is typically highest directly under the fixture and lower at the edges.
Efficiency (µmol/J) describes how much photosynthetically active light the fixture produces per joule of electricity consumed. A fixture rated at 3.0 µmol/J produces more usable light per watt than one rated at 2.0 µmol/J. Higher efficiency generally means less heat and lower running costs for the same light output.
Uniformity refers to how evenly PPFD is distributed across the coverage area. Bar-style fixtures with multiple light sources tend to produce more uniform distribution than single-point panel fixtures, particularly at lower hanging heights.
Fixture footprint matters because a physically large fixture distributes its diodes across a wider area, which can improve edge coverage and reduce hot spots. A compact panel concentrates its output in a smaller area.
Driver efficiency affects how much of the input power is converted to light versus heat. Higher-quality drivers waste less energy as heat, which also reduces the thermal load on your tent.
Dimming allows you to reduce output during propagation and early vegetative growth, then increase it as plants mature. A fixture without dimming capability runs at full power regardless of what your plants need at each stage.
How Much Light Does Your Growing Area Need?
Different growth stages and crop types have different light requirements. The following is general guidance only — specific targets will vary by species, cultivar, and growing method.
Propagation and seedlings require relatively low light intensity. Excessive intensity at this stage can stress young plants. A dimmable fixture run at reduced output, or a dedicated low-wattage light, is appropriate. The AC Infinity Ionboard S22 at reduced output or the Treegers bulbs are suitable for propagation applications.
Leafy vegetative growth — herbs, leafy greens, and plants in early vegetative development — generally requires moderate light intensity. Consistent, even coverage across the canopy is more important than peak intensity at this stage.
Flowering and fruiting plants — chillies, tomatoes, and other fruiting crops — typically benefit from higher light intensity during the reproductive stage. This is where higher-wattage, high-efficiency fixtures earn their place. The manufacturer's stated flowering coverage area is the relevant figure to use when sizing a fixture for this application.
Supplemental and under-canopy lighting is used to increase light reaching lower parts of the canopy that the primary fixture cannot adequately illuminate. The LFG Under Canopy LED and the AC Infinity Ionbeam S16 bars are designed for this application.
Grow Light Recommendations by Tent Size
Best Light Size for a 60 × 60 cm Tent
A 60 × 60 cm tent has a floor area of 0.36 m². A compact square panel is the most practical fixture shape for this space, as bar-style arrays are typically designed for larger areas.
The AC Infinity Ionboard S22 (100 W) is the only fixture currently listed at Green Genius with a stated coverage area matching 60 × 60 cm. It is dimmable from 0–100% and compatible with the AC Infinity UIS controller system. A single fixture is appropriate for this tent size.
Best Light Size for a 60 × 120 cm Tent
A 60 × 120 cm space has a floor area of 0.72 m². The rectangular shape suits a bar-style fixture or two smaller panels positioned end to end. No fixture currently listed at Green Genius states a specific 60 × 120 cm coverage area. The AC Infinity Ionbeam S16 bar kit can be used in a supplemental or low-intensity primary role for this space. For higher-intensity applications, contact Green Genius to discuss current stock options.
Best Light Size for a 90 × 90 cm Tent
A 90 × 90 cm tent has a floor area of 0.81 m². No fixture currently listed at Green Genius states a specific 90 × 90 cm coverage area. A fixture rated for 120 × 120 cm run at reduced output, or the Ionboard S22 used with supplemental bars, may be appropriate depending on your crop and growth stage. Contact Green Genius for current recommendations for this tent size.
Best Light Size for a 120 × 120 cm Tent
A 120 × 120 cm tent (1.44 m²) is one of the most common sizes for home growers and has the strongest product support in the current Green Genius range.
Three fixtures are currently listed with coverage data supporting this tent size:
- AC Infinity Ionframe EVO6 — 500 W, rated for 120 × 120 cm flowering coverage, 3.14 µmol/J efficiency, PPFD 1991, UIS controller compatible
- LFG 600 W LED — 600 W, rated for 120 × 120 cm to 150 × 150 cm, 3.2 µmol/J efficiency, built-in 0–100% dimmer
- LFG 720 W LED — 720 W, rated for 120 × 120 cm to 150 × 150 cm, 3.2 µmol/J efficiency, built-in 0–100% dimmer
A single fixture is appropriate for a 120 × 120 cm tent. The EVO6 is a bar-array fixture; the LFG options are panel-style. Bar arrays generally provide more uniform distribution at lower hanging heights.
Best Light Size for a 150 × 150 cm Tent
A 150 × 150 cm tent has a floor area of 2.25 m². Two fixtures are currently listed at Green Genius with coverage data for this size:
- AC Infinity Ionframe EVO8 — 730 W, rated for 150 × 150 cm flowering coverage, 3.14 µmol/J efficiency, PPFD 2013, UIS controller compatible
- AC Infinity Ionframe EVO10 — 1000 W, rated for 150 × 150 cm flowering coverage, 3.14 µmol/J efficiency, PPFD 2146, UIS controller compatible
Both are bar-array fixtures. The EVO10 provides higher PPFD for crops requiring greater light intensity. A single fixture covers this tent size. Ensure your tent's hanging bars and electrical circuit can support the fixture weight and power draw before purchasing.
Best Lighting Layout for a 120 × 240 cm Tent
A 120 × 240 cm tent has a floor area of 2.88 m². This rectangular space is best served by two fixtures positioned end to end rather than a single large panel, which would struggle to provide even coverage across the full length.
Two AC Infinity Ionframe EVO6 fixtures (500 W each, 1000 W total) would cover two 120 × 120 cm zones within the tent. Alternatively, two LFG 600 W or LFG 720 W panels could be used. The LFG 650 W Light Bar (rated for 150 × 120 cm to 180 × 150 cm) may also be suitable as a single fixture for part of this space, depending on your crop requirements. Verify total electrical load before purchasing two high-wattage fixtures.
Compare Green Genius LED Grow Light Brands
AC Infinity
AC Infinity offers the Ionboard S22 (compact panel, 60 × 60 cm coverage), the Ionframe EVO6 (bar array, 120 × 120 cm), EVO8 (bar array, 150 × 150 cm) and EVO10 (bar array, 150 × 150 cm), and the Ionbeam S16 supplemental bar kit. All bar-array fixtures use Samsung LM301H EVO diodes at 3.14 µmol/J efficiency and are compatible with the AC Infinity UIS controller ecosystem, enabling app-based scheduling, dimming, and integration with fans and environmental sensors. The Ionboard S22 uses Samsung LM301H diodes at 2.7 µmol/J. Browse: LED Grow Lights.
LFG
LFG offers three panel-style fixtures and one bar-style fixture currently listed at Green Genius. The 600 W and 720 W panels use Samsung LM281B+ Pro diodes at 3.2 µmol/J efficiency and cover 120 × 120 cm to 150 × 150 cm. The 650 W Light Bar uses a combination of white and deep-red LEDs at 2.9 µmol/J and covers 150 × 120 cm to 180 × 150 cm. The 120 W Under Canopy LED is designed for supplemental inter-canopy lighting at 2.9 µmol/J. All LFG fixtures include a built-in 0–100% dimmer knob and carry a 5-year warranty.
Treegers
Treegers offers two E27 screw-base LED grow bulbs: the 15 W (2.2 µmol/J, 30 µmol/s PPF) and the 30 W (60 µmol/s PPF). These are suitable for small ornamental plants, propagation, or supplemental lighting in confined spaces. No grow-tent coverage area is stated for either product. They are not dimmable and do not integrate with smart controllers.
Hanging Height and Dimming
Hanging height and output level work together to determine the intensity and coverage area your plants receive. The following principles apply broadly, but always refer to the manufacturer's recommendations for your specific fixture.
- Start conservatively with young plants. Seedlings and cuttings are sensitive to high light intensity. Begin with the fixture at a greater distance from the canopy and at reduced output if dimming is available.
- Use the manufacturer's recommended hanging height as your starting point. Stated coverage areas are typically measured at a specific hanging height. Deviating significantly from this height will change both the coverage area and the intensity at canopy level.
- Observe plant response. Signs of light stress include bleaching, upward leaf curl, and tip burn. Signs of insufficient light include stretching and pale colouration. Adjust height and output gradually in response to what you observe.
- Intensity changes with distance. Moving a fixture closer to the canopy increases intensity and reduces coverage area. Moving it further away reduces intensity and increases coverage area. This relationship is not linear — small changes in height can produce significant changes in PPFD at canopy level.
- A dimmable fixture offers flexibility. Rather than adjusting height alone, a dimmable fixture allows you to fine-tune output at a consistent hanging height, which is often more practical in a tent environment.
- Environmental conditions affect plant tolerance. Plants under heat or water stress may be less tolerant of high light intensity. Monitor temperature and humidity alongside light levels.
Operating Cost Calculator
Use the formula below to estimate the running cost of your grow light setup. Enter your own electricity rate — do not use a default figure, as electricity prices vary significantly across Queensland and Australia.
Formula:
Daily energy (kWh) = fixture wattage ÷ 1,000 × hours per day × number of fixtures
Worked example (hypothetical figures only):
- Fixture wattage: 500 W
- Hours per day: 18
- Number of fixtures: 1
- Electricity rate: [enter your own rate in $/kWh]
Daily energy = 500 ÷ 1,000 × 18 × 1 = 9.0 kWh/day
Weekly energy = 9.0 × 7 = 63.0 kWh/week
Monthly energy = 9.0 × 30 = 270 kWh/month
Multiply your kWh figures by your electricity rate ($/kWh) to calculate estimated cost. For example, at a hypothetical rate of $0.30/kWh: daily cost = 9.0 × $0.30 = $2.70. These are illustrative figures only — enter your actual rate and hours for an accurate estimate.
Common Grow Light Buying Mistakes
- Selecting by advertised model number instead of actual wattage. Some fixtures are marketed with a model number that implies a wattage (e.g. "1000W") that does not reflect actual power draw. Always check the stated input wattage in the product specifications.
- Ignoring fixture dimensions. A bar-array fixture designed for a 150 × 150 cm space may not physically fit or hang correctly in a 120 × 120 cm tent. Check the fixture's physical dimensions against your tent's internal dimensions and hanging bar positions before purchasing.
- Assuming maximum output is appropriate at every stage. Running a high-output fixture at full power over seedlings or young cuttings can cause stress. Use dimming or increase hanging height during early growth stages.
- Ignoring edge coverage. PPFD is typically highest directly under the fixture and lower at the edges of the coverage area. If uniform coverage across the full tent floor is important, check whether the fixture's PPFD map supports this.
- Buying before measuring the tent. Confirm your tent's internal dimensions — including height — before selecting a fixture. Hanging clearance between the fixture and the canopy is essential and is often underestimated.
- Failing to account for hanging clearance. The fixture, ratchet hangers, and any driver or cable assembly all consume vertical space. Measure from the tent's top cross-bar down and subtract the fixture height and hanger length to determine the minimum canopy-to-fixture distance achievable.
- Ignoring driver and room heat. LED fixtures produce less heat than HPS, but high-wattage fixtures still contribute meaningfully to tent temperature. Factor the fixture's heat output into your ventilation planning.
- Choosing incompatible controllers. AC Infinity fixtures use the UIS ecosystem. Ensure any controller you purchase is compatible with your specific fixture model before buying.
- Comparing watts without comparing efficiency or distribution. A 600 W fixture at 3.2 µmol/J delivers more usable light than a 600 W fixture at 2.0 µmol/J. Wattage alone is not a reliable basis for comparison.
Shop LED Grow Lights in Brisbane and Australia-Wide
Green Genius stocks a curated range of LED grow lights suitable for propagation through to high-intensity flowering applications. You can purchase online with delivery across Australia, or visit our Brisbane showroom to compare fixtures in person and speak with our team before you buy.
Green Genius Brisbane Hydroponics Store
Unit 16 / 71 Jijaws Street, Sumner QLD 4074
Phone: 07 3568 2957
Email: support@greengenius.com.au
Please contact us or check our website for current trading hours before visiting.
Shop LED Grow Lights | Shop Grow Tents | Shop All Grow Lights | Contact Us | Visit Our Brisbane Store
Frequently Asked Questions
What size LED grow light do I need?
The right size depends on your growing area's floor dimensions, your crop type, and the growth stage you are targeting. Start with the manufacturer's stated flowering coverage area and match it to your tent's floor area. Use the coverage chart above as a starting point, then check individual product listings for detailed specifications.
How many watts do I need per square metre?
Wattage per square metre is a rough planning guide, not a precise specification. Because fixtures vary significantly in efficiency (µmol/J), two fixtures with the same wattage can deliver very different amounts of usable light. Use the manufacturer's stated coverage area and PPFD data rather than relying on a watts-per-square-metre rule of thumb.
What light suits a 120 × 120 cm grow tent?
Based on products currently listed at Green Genius, the AC Infinity Ionframe EVO6 (500 W, rated for 120 × 120 cm flowering coverage), the LFG 600 W LED and the LFG 720 W LED (both rated for 120 × 120 cm to 150 × 150 cm) are suitable options. Verify specifications on the individual product listing before purchasing.
Can a grow light be too powerful?
Yes. Excessive light intensity — particularly over seedlings, cuttings, or plants under heat or water stress — can cause bleaching, tip burn, and other stress responses. A dimmable fixture allows you to match output to your plants' requirements at each growth stage.
Is one large light better than two smaller lights?
It depends on the shape of your growing area and the fixture's PPFD distribution. For square tents, a single well-matched fixture is often sufficient. For rectangular spaces such as a 120 × 240 cm tent, two fixtures positioned end to end typically provide more even coverage than a single large panel. Bar-array fixtures generally produce more uniform distribution than single-point panels.
What is PPFD?
PPFD stands for photosynthetic photon flux density. It measures the amount of photosynthetically active light arriving at a specific point on the canopy each second, expressed in µmol/m²/s. It is the most directly relevant measure of light intensity for plant growth. PPFD varies across the canopy — it is highest directly under the fixture and lower at the edges.
Does hanging height change coverage?
Yes. Raising the fixture increases coverage area but reduces intensity at canopy level. Lowering it increases intensity but reduces coverage area and can create hot spots. Always refer to the manufacturer's recommended hanging height for the stated coverage area.
Should seedlings use full power?
No. Seedlings and young cuttings are sensitive to high light intensity. If your fixture is dimmable, start at a reduced output level and increase gradually as plants develop. If your fixture is not dimmable, increase the hanging height to reduce intensity during early growth stages.
How much does an LED grow light cost to run?
Use the formula: daily energy (kWh) = fixture wattage ÷ 1,000 × hours per day × number of fixtures. Multiply by your electricity rate ($/kWh) to calculate daily cost. See the worked example in the Operating Cost Calculator section above. Electricity prices vary — enter your own rate for an accurate estimate.
Can Green Genius check whether a light fits my tent?
Yes. Contact our team by phone on 07 3568 2957 or by email at support@greengenius.com.au, or visit us in person at our Sumner store. We can help you confirm that a fixture is appropriate for your tent size and growing goals before you purchase.