PHILIPS C150S55/ALTO CERAMALUX HIGH PRESSURE SODIUM LAMP 150W 55V BULB LIGHT

Lower Maintenance Costs Philips Ceramalux Non‑Cycling HPS lamps are built for long life and reliable performance, helping reduce replacement frequency and overall maintenance costs.

Universal Operating Position Fits standard E39 mogul sockets and can operate in any position, making it easy to install in most HPS fixtures.

ALTO® Non‑Cycling Technology Designed to prevent end‑of‑life cycling, keeping your lighting stable and predictable.

Warm 2100K Spectrum Produces a deep orange‑red light ideal for supporting flowering and fruiting stages.

High Efficiency Rated at 96–106 lumens per watt, delivering strong output with low energy use.

Low Color Rendering (CRI 21) This lamp is optimized for plant productivity, not visual color accuracy — normal for HPS.

What You Can Grow With a 2100K HPS Lamp

A 2100K high‑pressure sodium lamp is flower‑biased, meaning it excels at blooming, fruiting, and late‑stage production. It is not ideal for vegetative growth alone, but it can be paired with MH/CMH/LED for full-cycle gardens.

Best Uses (Flowering & Fruiting)

• Cannabis (flowering stage) Strong red spectrum promotes bud development, density, and yield.
• Tomatoes Encourages fruit set and ripening.
• Peppers (sweet & hot) Supports flowering and fruit production.
• Cucumbers Helps drive flowering and fruiting.
• Strawberries Good for bloom and fruit formation.
• Flowering ornamentals Chrysanthemums, gerbera, dahlias, hibiscus, roses.

Acceptable Uses (with supplemental veg lighting)

• Leafy greens (only if paired with blue‑heavy light) HPS alone causes stretching.
• Herbs Basil, mint, cilantro — again, best with added blue spectrum.

Not Ideal For

• Seedlings
• Clones
• Early vegetative growth
• Compact, tight‑node plants Because the 2100K spectrum lacks blue light, plants stretch and become leggy.