What height should I start at for each tent size?

As a starting point, use 10–14 inches in 2×2 tents, 12–16 inches in 2×4 tents, 12–18 inches in 3×3 tents, and 14–20 inches in 4×4 tents. Lower for veg-level PPFD targets, raise for higher wattage or to widen coverage, and then adjust in 1–2 inch steps based on your PPFD readings.

LED Layouts by Tent Size (2×2, 2×4, 3×3, 4×4)

Q: What’s the best way to space LED bars?

Split the area into equal lanes, keep 6–8 inches from tent walls and 4–6 inches between bars. For 2×4 tents use two long bars or four bars evenly spaced, for 3×3 run 6–8 bars in a grid with a small center gap to reduce hotspots, and for 4×4 use 8–10 bars and balance overlap zones to lift the edges.

Q: Can I mix different fixtures or wattages?

Yes. Match spectrum as closely as you can and dim them to blend. Place the higher-output fixture slightly higher or off-center, dim panels 10–20 percent when adding sidebars, offset seams between two panels by a few inches, and always re-check a 9-point PPFD map after changes.

Builder’s guide to LED tent layouts: recommended watts, bar/panel placement, hanging heights, and how to measure PPFD for uniform results.

9 de noviembre de 2025 3 min de lectura

Use this step-by-step to size watts, place bars and panels, and tune for even in popular tent sizes.

Even LED coverage over cilantro in a small grow tent.

Step 1 Pick your PPFD target

Seedlings / clones: 150–300 µmol/m²/s
Leafy herbs & greens: 300–500 µmol/m²/s
Fruiting / flowering crops: 600–900 µmol/m²/s

Aim for ≥ 0.8 (min ÷ max) across the canopy.

Step 2 Choose a modern watt range

Rule of thumb with efficient fixtures (≥2.7 µmol/J):

Tent	Typical watts	Notes
2×2	100–150 W	Compact panel or 2 mini bars
2×4	200–320 W	Two long bars or a 4-bar unit
3×3	250–400 W	6–8 bars or panel plus sidebars
4×4	400–650 W	8–10 bars or two 240–320 W panels

Step 3 Place the fixtures

Keep 6–8″ from tent walls and drivers for airflow. Start with the heights below, then fine-tune.

2×2 layout

Height: 10–14″. Center a compact panel or run two mini bars in parallel.

2×2 tent with a compact LED above four pots.

2×4 layout

Height: 12–16″. Two long bars lengthwise, or a 4-bar frame evenly spaced.

2×4 tent with two long LED bars over eight pots.

3×3 layout

Height: 12–18″. Six–eight bars in a grid, or one panel plus sidebars to lift edges.

3×3 tent with a multibar array above nine pots.

4×4 layout

Height: 14–20″. Eight–ten bars, or two mid-size panels with a slight overlap zone.

4×4 tent with two LED panels over sixteen pot positions.

Drivers & cable management

LED driver mounted high with tidy cabling in a grow tent.

Step 4 Measure & tweak

Hot center: raise 2–4″ or dim 10–20%.
Dark corners: drop 1–2″, add sidebars, or widen spacing.
Too low overall: lower height or increase output.

Re-measure at the and repeat until the map evens out.

How to re-measure at the canopy

PAR probe at canopy height in a multibar LED tent.

Use a for true readings. Phone are OK for relative checks only.
Set the probe at canopy height (top leaves). Turn fans down briefly to steady the reading.
Measure a 9-point grid: center, mid-edges, and corners. Note min, max, and average.
Calculate uniformity: min ÷ max. Target ≥ 0.8.
Adjust: raise / lower 1–2″, dim 5–10%, or nudge bar spacing; then re-measure the same 9 points.

Tip: If you must convert lux → PPFD for white LEDs, treat it as an estimate only—each spectrum is different.

FAQs

What’s the best way to space LED bars?

Quick answer: split the area into equal lanes; keep 6–8″ from walls and 4–6″ between bars.

2×4: two long bars lengthwise or four bars evenly spaced.
3×3: 6–8 bars in a grid; leave a small center gap to reduce hotspots.
4×4: 8–10 bars; balance overlap zones to lift edges.

Can I mix different fixtures or wattages?

Yes— just match spectrum and dim to blend. Place the higher-output unit slightly higher or off-center.

Panel + sidebars: dim the panel 10–20% to lift edges evenly.
Two panels: offset the seam by 2–3″ to reduce a hot stripe.
Always re-check a 9-point PPFD map after any change.

What height should I start at for each tent?

Starting points: 2×2: 10–14″, 2×4: 12–16″, 3×3: 12–18″, 4×4: 14–20″.

Lower for veg targets; raise for higher watts or to widen coverage. Adjust by 1–2″ and re-measure.

PPFD

Usable light at the canopy in µmol/m²/s.

Uniformity

How even the light is: lowest PPFD divided by highest. A result ≥ 0.8 is considered good.

Canopy

The top leaf layer of your plants. This is the reference height for all PPFD measurements.

PAR meter

A handheld sensor that measures photosynthetic light (PPFD) directly. Best tool for dialing in LEDs.

Lux app

A phone light meter. Useful for before/after comparisons, but lux → PPFD conversions are only rough estimates.

Not sure if your layout is really even?

Share your tent size, fixture model, and a quick PPFD or lux map. We’ll suggest bar spacing, height, and dimmer settings so you hit your targets without guesswork.

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