GrowLite 315W Single Ended Mogul Base Full Spectrum Ceramic Metal Halide Lamp

Growlite 315W mogul base full-spectrum CMH lamp for single-ended reflectors

Growlite sells this as part GLL-315-CSI, a 315W ceramic metal halide lamp in a large ED37 envelope with a screw-in mogul base. The spec sheet lists 521 µmol/s of PPF and 32,790 lumens after 100 hours, about 104 lm/W. Colour temperature is 4000K with a CRI of 95. Rated life runs to 20,000 hours on Growlite's sheet. It runs at a nominal 100V and 3.15A on an ANSI C182/O-rated ballast. The lamp measures 292 mm (11.5 in) overall with a 178 mm light centre length and a 121 mm (4.75 in) bulb diameter. Growlite rates it for open or enclosed fixtures and a universal burning position. That envelope is much bigger than a PGZX18 lamp. It is sized like a standard mogul HID bulb, so it sits where the old lamp sat in a single-ended hood. Growlite also makes a slimmer T15 mogul version and a double-ended lamp in the same line.

Using an E39 mogul base CMH lamp in an existing reflector

The mogul base is the whole point of this lamp. It screws straight into the socket of a single-ended HPS or MH reflector, so no socket adapter is needed. The socket is only half the job, though. It still needs a ceramic metal halide ballast, because a magnetic or digital HPS ballast will not drive it properly. Before you swap it in, confirm the reflector's socket and wiring are rated for a lamp of this size and heat. At this colour temperature it sits in the transitional band, so one lamp can carry a room from veg through harvest. Growers chasing maximum bloom output tend to run a warmer lamp near 3000K instead. Start it high over young plants and bring it down as the canopy fills and the stretch finishes. Like every ceramic metal halide lamp it emits UV, so wear CMH-rated eyewear such as Summer Blues Optics glasses when working under it. Growlite publishes no UV figure, and this lamp was not part of our own CMH comparison test.

Key Features

• E39 Mogul Base: Screws into standard single-ended HID sockets with no PGZX18 adapter.
• 521 µmol/s PPF: A published photon figure makes canopy planning straightforward.
• 32,790 Initial Lumens: Around 104 lm/W keeps heat and power draw moderate for the output.
• 4000K, CRI 95: A balanced spectrum carries plants from veg into flower without a lamp change.
• Open or Enclosed, Any Position: Runs bare in open hoods or behind glass, at any mounting angle.
• 20,000-Hour Rated Life: Long rated life stretches replacement intervals across many cycles.

Technical Specifications