Ushio HiLux Gro CMH 315W 3000K Bloom Lamp | 620 µmol/s, CRI >90

Ushio HiLux Gro CMH 315W 3000K, the warm lamp in the HiLux Gro line

This is the bloom-spectrum 315W ceramic metal halide lamp from Ushio, sold as model CMH-315W/930/AGRO under product number 5002536. Ushio rates it at 33,000 lumens after 100 hours, or 110 lm/W, the higher efficacy of the two HiLux Gro colour points. Its brochure lists 620 µmol/s of PPF, and colour rendering sits above CRI 90. Rated life is 15,000 hours on ten-hour starts. The lamp runs at 100V and 3.15A, needs a 4 to 5 kV starting pulse, and pulls 4.7A while it warms up. It sits on a PGZX18 base inside a clear, double-envelope T12 bulb that measures 193 mm end to end. Ushio rates it for open or enclosed fixtures, burning anywhere from base-up to horizontal. The ballast match is an ANSI C182/O-rated ballast or an electronic CMH ballast. After a power cut, give it 6 to 8 minutes to cool before it will restrike. That wait is normal for ceramic lamps.

A 315W CMH bulb for flowering that led our UV readings

In our own ten-lamp CMH comparison, this lamp posted the highest UV reading of the group, measured between 250 and 400 nm at 24 inches. It finished seventh of ten on summed PAR, so it was not the brightest lamp we tested. The spread from first to last on PAR was under 16%, though, so the photon gap is small. That trade is the reason to pick it: close to the leaders on photons, with more of the short-wave band growers chase late in flower. At this colour temperature it sits in the bloom and transitional range, warm enough to carry a crop from flip to harvest. Over a 3x3 or 4x4 tent, most growers start it around 18 to 24 inches above the canopy and lower it once the stretch ends. Open reflectors are fine here, because Ushio rates the lamp for open and enclosed fixtures alike. Drive it with a low-frequency CMH ballast, since a standard HPS or MH ballast will not run it. It is a lamp only, so the socket, reflector and ballast all come from elsewhere. Our UV figure is relative within the CMH class and came from one test rig, not a lab sphere. For a veg room, the 4200K lamp in the same line is the better call.

Key Features

• 620 µmol/s PPF: Ushio's published photon figure is the higher of the two HiLux Gro 315W lamps.
• Top UV Reading in Our Test: It led ten 315W CMH lamps on UV between 250 and 400 nm at 24 inches.
• 110 lm/W Efficacy: More light per watt keeps heat and power draw down in a sealed flower room.
• 3000K Bloom Spectrum, CRI >90: Warm output carries flowering while leaf colour stays easy to read.
• 15,000-Hour Rated Life: Long rated life on ten-hour starts means fewer lamp changes per year.
• PGZX18, Open or Enclosed: The standard single-ended 315W base fits common CMH reflectors either way.

Technical Specifications