Description
Professional Sodium Light for Strong Growth and Heavy Flowering
The Osram Plantastar HPS Lamp is a clear tubular high-pressure sodium lamp from Osram's horticultural range, built for greenhouse and indoor growing. It comes as a 400W, 230V lamp for standard 400W ballasts, rated by Osram at 56,500 lumens and 725 µmol/s, and a 600W, 400V lamp rated at 86,500 lumens, both on a standard E40 screw cap. The spectrum is tuned for photosynthesis rather than street lighting, and Osram rate both lamps to keep over 90% of their photon flux after 12,000 hours, so light levels at the canopy stay where you set them through many cycles. The 600W version is made for 400V gear – the ballasts and professional greenhouse fittings that run a 600W lamp from a 400V supply – and both suit flowering and fruiting crops in a grow tent, grow room or greenhouse.
Key Benefits
- 400W and 600W horticultural HPS – Osram's Plantastar lamp, designed for plant growth rather than street lighting
- 56,500 lumens at 400W and 86,500 lumens at 600W (about 141 and 138 lm/W) for strong canopy intensity
- Over 90% photon flux maintained at 12,000 hours – slow, even ageing and fewer lamp changes
- Two supply versions – the 400W runs on standard 230V HPS ballasts, the 600W on 400V ballasts and professional fittings
- Robust ceramic arc tube in a compact clear tubular envelope 28.5 cm long, on a standard E40 cap
The Hidden Cost of a Tired Lamp
An HPS lamp rarely fails outright; it fades. As output drops the canopy receives less light, and the signs creep in slowly: slower growth, excessive stretch between nodes and lighter flowering in a room where nothing else has changed. A lamp that keeps its photon output for longer holds light intensity steady through the season, and matching the lamp voltage to the ballast makes sure you get the full rated output and life rather than a lamp that runs dim or fails early.
How to Use
- Check the gear first: fit the 400W, 230V lamp to a standard 400W HPS ballast, and the 600W, 400V lamp only to a ballast or fixture rated to run a 600W lamp at 400V
- Power off and cool down: isolate the light and let the old lamp cool fully before removing it
- Handle with care: hold the lamp by its cap or wear clean gloves, and screw it firmly into the E40 holder
- Hang at the right height: start high over young plants and lower gradually, using a PAR meter or the leaves as your guide – the area lit well depends on your reflector and hanging height
- Relamp on a schedule: Osram recommend replacing Plantastar lamps after 12,000 hours for steady growth, rather than waiting for one to fail
Technical Specifications
- Brand: Osram (PLANTASTAR-T range)
- Type: high-pressure sodium (HPS), clear tubular
- Wattage: 400W, 600W
- Supply voltage: 230V on the 400W (standard ballasts); 400V on the 600W (needs 400V-rated gear)
- Cap/base: E40
- Light output (Osram): 56,500 lumens (400W); 86,500 lumens (600W, 400V)
- Efficacy: approx. 141 lm/W (400W); 138 lm/W (600W, 400V)
- Photon flux (Osram): 725 µmol/s (400W)
- Colour temperature: approx. 2000K
- Photon flux maintenance: over 90% at 12,000 hours
- Lamp size: 28.5 cm long, 4.6–4.7 cm diameter (both wattages)
- Light centre length: 17.5 cm
- Burning position: any
- Recommended replacement: after 12,000 hours (Osram)
- Best stage: flowering and fruiting
Frequently Asked Questions
Will the 600W lamp work in my standard 600W ballast?
The 600W Plantastar sold here is the 400V version, so only if the ballast is rated to drive a 400V lamp. Most hobby magnetic and digital 600W ballasts run 230V lamps – check the ballast label or manual for 400V lamp support before fitting. The 400W Plantastar is a standard 230V lamp for 400W ballasts.
Why does the 600W need 400V gear?
It is Osram's 400V Plantastar, built for ballasts and fittings that run the lamp from a 400V supply, typically in commercial greenhouses. It will not run correctly on a standard 230V 600W ballast, so check your gear before ordering.
How often should I replace it?
Osram rate it to keep over 90% of its photon flux at 12,000 hours and recommend replacing it at that point. Relamp sooner if PAR readings at the canopy have dropped.
Can I use it for vegetative growth?
Yes, it will grow plants through every stage, but HPS light is strongest in the orange and red, so it is at its best in flowering and fruiting; many growers use a metal halide or LED for vegetative growth.
Works Well With
