Grow lights replace the sun in a grow tent: here you will find full-spectrum LEDs from Lumatek and Lumen-King, HPS sodium kits and replacement bulbs. For flowering, allow about 300–400 W of actual LED power per m², which means 100–150 W for a 60x60 and 400–600 W for a 120x120. All LED models are in the LED grow lights section.
For a home grow tent, LED is now the normal choice. For the same amount of light it uses about 30–50% less electricity than an HPS sodium lamp, puts less heat on the tops and has no bulbs to replace; with a dimmer, the same light covers seedlings, the vegetative stage and flowering. HPS is cheaper to buy and still makes sense in a cold room, such as a cellar below 15 °C in winter, where its heat is useful.
| Feature | LED | HPS (high pressure sodium) |
|---|---|---|
| Efficiency | 2.5–2.9 µmol/J | 1.3–1.8 µmol/J |
| Power for similar light | 240 W | 400 W |
| Distance in flowering | 30–45 cm | 40–60 cm |
| Heat on the tops | low | high, more extraction needed |
| Stages | all, by adjusting intensity | mainly flowering |
| Spare parts | none for years | bulb every 1–2 years |
What counts is the actual power drawn from the socket, not the "equivalent watts" printed on the box. In flowering you need about 300–400 W of actual LED power per m²; in the vegetative stage 50–75% is enough, set with the dimmer.
HPS needs more watts for the same light: a 250 W kit covers a 60x60, a 400 W kit an 80x80 and at most a 100x100. Complete kits with ballast and reflector are among the HPS grow light kits, Philips and Osram replacements among the HPS bulbs. For the tent size, see the grow tents.
Lumatek: Zeus LEDs at 465, 600 and 1000 W (PRO and Xtreme versions), compact ATS LEDs at 200 and 300 W, and 250 W and 400 W HPS kits with reflector. Lumen-King: Eco-Line LEDs at 400, 720 and 1000 W and Professional Line at 465 and 630 W. Philips and Osram: Son-T, Son-T GreenPower and Plantastar HPS bulbs from 250 to 600 W.
Prices are in Swiss francs including Swiss VAT. We ship throughout Switzerland with Swiss Post, and bulky parcels go by courier. For help with choosing the right light for your tent, ask the Gro.w.LaB team: contact us by email, call +41 79 359 67 58 or visit the shop in Quartino by appointment.
In a home grow tent, yes: for the same light an LED uses about 30–50% less electricity, runs cooler and has no bulbs to replace. HPS makes sense if you already own one or grow in a cold room.
In flowering, about 300–400 W of actual LED power with an efficiency of at least 2.5 µmol/J. In the vegetative stage, 50–75% of that power is enough.
At 12 hours a day, 0.6 kW × 12 h × 30 days = 216 kWh, about 65 CHF at 0.30 CHF/kWh. At 18 hours it is 324 kWh, about 97 CHF.
An LED at full power hangs 30–45 cm above the tops in flowering, 40–60 cm in veg and 50–75 cm for seedlings; an HPS 40–60 cm in flowering. Always check the manufacturer's instructions as well.
