HPS grow lamps from 250W to 600W are the single-ended workhorses of indoor growing – E40 screw fitting, standard reflectors, and decades of proven flowering performance behind them.
Which wattage
Lamp
Covers
Extraction
250W
60 x 60cm
4in fan and filter
400W
100 x 100cm
4-5in
600W
120 x 120cm
5-6in
600W is by far the most common – it matches the 1.2m tent, which is the standard UK footprint. See 1.2m grow tents.
They wear out before they fail
This is the thing that costs people yield without them noticing. An HPS lamp loses output steadily from the day it is switched on while drawing exactly the same electricity. By eighteen months you are paying full price for meaningfully less light. Replace annually, or every two to three cycles – a new lamp is cheaper than the yield a tired one costs you.
Dual spectrum or standard?
Standard HPS is red-heavy and built purely for flowering. Dual spectrum adds blue so one lamp covers veg and flower – convenient, slightly compromised at both ends. If you run separate veg and flower spaces, use metal halide for veg and straight HPS for flower.
Handling
Never touch the glass with bare fingers. Skin oil creates a hot spot that shortens life or cracks the envelope. Cloth or gloves, and let it cool fully before removing.
Check the fitting
These are single-ended E40. Double-ended lamps use K12x30 and need a DE reflector and a 400V ballast – not interchangeable. See 1000W 400V DE lamps, ballasts and reflectors.
Why buy lamps from The Hydro Bros?
We are a hydroponics shop in Croydon with fresh stock rather than lamps that have sat for two years. Tell us your ballast and we will match it. Discreet UK and European delivery, and excellent customer reviews on Trustpilot.
