Choosing the right 400 watt high pressure sodium (HPS) bulb can improve bloom yield and overall plant vigor. This guide highlights well-regarded options, compares lumen output, color temperature, and compatibility, and provides practical buying guidance for home growers and small urban gardens.
| Product | Base / Type | Lumens | CCT (K) | |
|---|---|---|---|---|
| GRUOTVSZAK HPS 400W Bloom Bulb | E39 Mogul | 55,000 | 2000–2100 | Unknown |
| Sunlite 03636-SU LU400/MOG | E39 Mogul | 48,000 | 2100 | 20,000 |
| GRUOTVSZAK LU400/MOG 400W | E39 Mogul | 50,000 | 2100 | 24,000 |
| Vegelumax 400W HPS | E39 Mogul | 55,000 | 2100 | 5,000 |
| iPower 400W HPS Grow Light Bulb | E39 Mogul | 55,000 | 2100 | 6,500 |
Note: All bulbs listed are designed for hydroponic or horticultural use and integrate with standard HPS fixtures. When selecting a bulb, consider lumen maintenance over time and the spectrum bias toward red for flowering stages.
GRUOTVSZAK 400W HPS Bloom Light Bulb
Brand: GRUOTVSZAK. This bulb features a high yield of 750 μmol/s and about 55,000 lumens, emphasizing red-dominant spectrum to maximize photosynthesis during flowering. It is compatible with both electronic and magnetic ballasts and uses an E39 base. The design targets blooming by boosting red PAR focus for larger buds.
Sunlite 400W HPS LU400/MOG Bulb
Brand: Sunlite. This ED18/MOG 400W lamp delivers about 48,000 lumens with a 2100K color temperature, tuned for strong flowering performance. The clear glass bulb and standard E39 base suit many HID fixtures, with a practical 20,000-hour life suitable for steady garden cycles.
GRUOTVSZAK LU400/MOG 400W HPS Bulb
Brand: GRUOTVSZAK. This 2100K ET18 clear bulb offers around 50,000 lumens with a Mogul E39 base. It emphasizes compatibility with ANSI S51 ballast and provides a robust long-life profile for cultivation cycles requiring consistent bloom timing.
Vegelumax 400W HPS Super Grow Light Bulb
Brand: Vegelumax. This 2100K bulb emits about 55,000 lumens with a red-orange spectrum designed for professional hydroponic growth. The E39 base ensures broad ballast compatibility and strong flowering performance with good lumen maintenance over time.
iPower 400W HPS Grow Light Bulb
Brand: iPower. This 400W HPS bulb offers 55,000 lumens with 2100K CCT and an E39 base, optimized for flowering with a spectrum rich in red and orange. It features early lumen depreciation protection to maintain high output during extended grow cycles.
Buying Guide: Key Considerations For 400W HPS Bulbs
Purpose and spectrum: For flowering, look for bulbs in the 2100K range with strong red and orange components to boost bud development and fruiting while maintaining adequate PAR for photosynthesis.
Lumens and lumen maintenance: Higher initial lumens support rapid bloom; check lumen maintenance ratings to gauge performance over time, especially if you run long cycles.
Ballast compatibility: Ensure the bulb matches your ballast type (electronic or magnetic) and ballast ANSI code if specified. A correct match reduces risk of arcing and inefficiency.
Life hours: Longer life reduces maintenance, especially in commercial or multi-cycle setups. Compare claimed life hours to real-world expectations in horticultural use.
Base and form factor: Most HPS bulbs use an E39 mogul base. Verify your fixture’s socket size and clearances before purchasing to avoid fit issues.
Quality and brand reliability: Reputable brands with horticulture-focused specs typically offer more stable spectra, better lumen maintenance, and consistent performance across batches.
Cost of ownership: Consider bulb price, replacement frequency, and energy efficiency relative to expected yield improvements to determine total cost of ownership for your grow operation.