A 400W HPS lamp is a sensible choice for small tents around 60x60 to 80x80 cm, or as extra light in a corner of a larger room. It runs cooler than higher wattages, which makes the climate easier to manage in a compact space. Right now you'll find the GE Current Lucalox 400W bulb here, a classic high-pressure sodium lamp with a warm spectrum for flowering. Use it with a matching 400W ballast and an E40 reflector. For more light per square metre, take a look at 600W HPS lamps or the full HPS lamps range.
Questions & answers about 400W HPS Lamps
All growing questions →- Lighting LED or HPS: which grow light is better? LED, for most people with a tent. It's more efficient, makes less heat and the diodes last years. HPS costs less to buy but needs more ve... Read the answer →
- Lighting How many lumens does a grow room need per square metre? None, really. Lumens measure what your eye sees. Plants use PPFD, in µmol/m²/s, so compare lamps on that. Read the answer →
- Lighting How many hours of light do plants need in veg and in flower? Photoperiod plants usually get 18 hours on and 6 off in veg, then 12 on and 12 off to flower. Autoflowering plants can stay on 18/6 or up... Read the answer →
- Problems & pests What is light burn and how do I stop it? Light burn shows as bleached, yellow or crispy leaves at the top, closest to the lamp. Raise the lamp or dim it. Read the answer →
