The right LED grow light matches your tent's growing area, your plants' requirements and the space available above them. Wattage helps you compare electrical demand, but it cannot tell you how evenly a fixture lights the canopy. Start with dimensions and growth stage, then check the exact light's specifications, PPFD map and installation instructions.
Start with the footprint and the plants
Measure width and depth, then decide how much of that floor area will actually hold a canopy. A rectangular 120 × 60cm tent needs a different light spread from a square tent. Check the fixture's physical dimensions too: a light must fit without obstructing ducting, extraction equipment or access.
Think about what you will grow and which stages the tent will support. Seedlings, leafy plants and flowering or fruiting crops can have different lighting requirements. Two pots do not define a lighting requirement: pot size, plant size and canopy arrangement also matter. Our grow tent size guide helps you plan the space before choosing equipment.
Read input power, rather than the model number
Look for actual electrical input power in the manufacturer's specification sheet. A model number is an identifier, while an HPS-equivalent label is a comparison claim; neither should be treated as the fixture's consumption at the socket.
For example, Spider Farmer lists the SF1000's power draw at approximately 100W, rather than the 1,000W its name might suggest. Use the specification for the exact version you are buying. Input can change with dimming and operating conditions, so the product name alone is unsuitable for calculating running costs or choosing extraction.
Compare PPFD across the growing area
PPFD, or photosynthetic photon flux density, measures the photosynthetically active light reaching an area at a particular moment. A PPFD map shows readings across a measurement grid. Look at the edges and corners as well as the centre: one impressive central reading does not describe the whole canopy.
Compare maps taken over the same area, at the same height and dimming setting. Check whether the manufacturer distinguishes vegetative and flowering coverage. Where possible, use a suitable PAR meter to check your actual arrangement. Avoid choosing a light from watts alone or treating a single watts-per-square-metre rule as a guarantee for every crop.
Examples from our current equipment bundles
These are verified pairings sold together by The Grow Fellas. They reproduce bundle contents, not universal coverage recommendations or promises for every plant and growth stage. Confirm the exact fixture's instructions before deciding which pairing suits your intended canopy.
| Bundle tent, width × depth × height | Listed LED fixture | Equipment bundle |
|---|---|---|
| 70 × 70 × 160cm | Spider Farmer SF1000 100W | Spider Farmer Starter Set |
| 100 × 100 × 180cm | Mars Hydro FC-E3000 300W | Mars Hydro Complete Set |
| 120 × 60 × 180cm | Mars Hydro FC-4000 320W | Mars Hydro DWC Set |
| 120 × 120 × 200cm | Spider Farmer G5000 480W | Spider Farmer Advanced Set |
Check the growth stage, dimming and hanging space
A light's intended use matters as much as its size. The LUMii BLACK Blade 100W is for propagation and vegetative growth; the supplier does not recommend it for flowering or fruiting. The LUMii Solar 315W kit is CDM lighting, so it should not be compared as though it were an LED fixture.
Follow the current manufacturer's hanging-height and dimming instructions for the exact model, version and growth stage. Measure the gap to the canopy, and allow for pots, mature plant height, hangers, the fixture and overhead equipment. A distance copied from another model can be unsuitable even when both lights have similar wattage.
Dimming arrangements vary. A stepped dimmer, an onboard dial and an optional external controller are different features. Check what is included and which controls are compatible; do not assume every light in a brand's range offers the same adjustment.
Match the light to the room as well as the tent
LED lighting still adds heat to the growing space. Plan extraction and replacement air around the installed equipment and the room's conditions. A clip fan moves air inside the tent; it does not replace an extraction system. Keep the manufacturer's ventilation and clearance requirements for the light and driver in your layout.
Before buying, compare your shortlist in our grow lights collection, or browse complete grow sets to see the listed components together. Use our complete grow kit checklist to check what else your setup needs.