Lumen King LED: choosing 400W, 720W or 1000W ECO

Start with the space you can actually light

Measure the internal width and depth of the growing space and establish the clearance above your plants. Allow room for hanging hardware, power supplies and air circulation. Fixture dimensions tell you whether it fits; distribution tells you whether the entire canopy receives suitable light.

We do not choose a Lumen King LED grow light using a fixed watts-per-square-metre rule. Crop, growth stage and operating hours also matter. A large fixture leaving too little clearance is a poor choice for a compact tent.

How do the three ECO models compare?

• 400W ECO: 400W nominal power and 1080 µmol/s PPF. Its 75 × 75 cm fixture size helps assess physical fit, but does not establish a fixed growing area.

• 720W ECO: 720W nominal power and 1944 µmol/s PPF. Check available width, hanging clearance and distribution across the complete growing area.

• 1000W ECO: 1000W nominal power and 2900 µmol/s PPF. Extra output requires a suitable lighting plan, adjustment range and climate control.

PPF is total photon output from the fixture. It does not describe the light received by an individual plant. Assess PPFD at several points across the canopy. The same fixture can produce very different results when positioning or dimming changes.

Keep the 630W series separate

The Lumen King 630W belongs to a different generation from the ECO models. Do not automatically transfer the supply, connections or control settings from an existing 630W setup to a 720W ECO. Establish the exact model and which components you intend to retain.

Before buying, check whether your version uses a separate ballast or an integrated driver and which supply is included. Fixture wattage and a rating on a separate ballast do not necessarily describe the same thing. Combine only components intended for the exact version.

Compare electricity consumption properly

Use actual input watts ÷ 1000 × operating hours = kWh. Over twelve hours, an actual draw of 400W uses 4.8 kWh, 720W uses 8.64 kWh and 1000W uses 12 kWh. Multiply this by your electricity tariff.

These are calculation examples based on those input powers, rather than measured consumption figures. A dimming setting or controller display is not automatically the power drawn at the socket. Measure the complete combination when using a separate supply, and add ventilation separately. Compare distribution at the setting you will actually use.

Choose in this order

1. Record the growing area, usable height and plant requirements.

2. Check physical fit including hanging equipment and power supply.

3. Assess output and distribution at a workable height and dimming level.

4. Verify power supply, controls and cables for the exact model.

5. Calculate energy use and assess heat removal for the complete setup.

Then refine placement with our Lumen King hanging height and dimming guide. For central control of several fixtures, use our Lumen King controller guide.