SunPulse 400W MH Pulse Start 4K


Learn more about SunPulse Lamps at

SunPulse Pulse Start Metal Halide Grow lamps were created by the GAS Technologies group of photo-biologists, plant scientists, mechanical and electrical engineers, gas chemists, and HID lamp designers. They are designed with true solar symmetry for true photochemical reactions in living organisms, greater molecular efficiency in operations, and better color rendering. Sun Pulse lamps are made with the highest quality and quality control.

* Available in Kelvin ratings of 3k, 4k, 6.4k, & 10k

* Designed to work with certified electronic and digital electronic ballasts

* Even lamp life approx (20,000 hrs) with little color shift or loss of FT-CD output

* SunPulse lamps are also available for 600W magnetic ballasts in the various colors!


0.4 lbs.
11.3L x 2.5W x 2.5H
Mogul (E39)
Metal Halide
1 Year

Which lamps are recommended for use with the Phantom and Xtrasun digital ballasts?

Most lamp brands distributed by Hydrofarm are approved for use in the our digital ballasts. Contact us to find out most up to date compatibility information.

My new bulb isn't lighting up, or only lights up sometimes. How can I fix this problem?

The problem might be a bad connection in the mogul socket. Make sure to disconnect the unit from the power supply, and then look inside the mogul socket for a metal tab. Pry this tab upwards a little bit to make better contact with the bulb base.

What is the importance of color temperature ratings (Kelvin) on bulbs (3000K, 6400K, etc.)?

Kelvin is a unit of measure that rates color temperature of a light source. Lower Kelvin temperatures will display deeper hues of red and orange light. Higher Kelvin temperatures emit deeper concentrations of blue light. As a general rule, one should use lamps with lower Kelvin temperatures for fruiting/blooming/flowering and lamps with higher Kelvin temperatures for vegetative growth.

How often should I replace my grow bulbs?

Whether fluorescent, sodium, or halide, we recommend replacing light system lamps (bulbs) every 1 to 1.5 years if operated for a minimum of 12 hours per day. Although lamps older than this might still ignite for multiple years, the quality of light they provide to the plants will have significantly degraded after this time of continuous use. (NOTE: The above does not apply to LED lamps, which have much longer service lives).