Veg vs Bloom Requirements

LEC 315: Ceramic Metal Halide Technology


LEC 315 lighting fixture

LEC 315

In the world of HID lighting for horticulture, Double Ended (DE) fixtures have been getting all the attention lately, but there is another “new” HID fixture that some growers may have naturally overlooked. Ceramic Discharge Metal halide (CDM) also marketed as Ceramic Metal Halide (CMH) and Light Emitting Ceramic (LEC). All of these are in fact the same technology. Ceramic lamps tend to run at a lower, fixed wattage, and their potential to save energy is often their most touted feature, so they may not be as exciting as that fully adjustable DE fixture that you can crank all the way to 1175watts. To fully appreciate the difference and why they deserve your attention, It’s best to see plants growing under an LEC first hand. Here are some of the reasons why you should take a field trip to your local Way to Grow today to see the difference for yourself.


Quality over Quantity


Ceramic lighting tech has actually been available for some time. They were first marketed for use in retail and commercial fixtures as an alternative to unnatural looking yellow-orange HPS bulbs or traditional Metal Halides which dim and burn out more quickly. Similar to a standard HPS bulb except the filament runs at a higher temperature giving them a high Color Rendering Index (CRI), truer to natural sunlight. The upshot was a lamp with the long life of a HPS. As well as a spectrum that couldn’t be matched by the best metal halides, and also capable of putting out excellent PAR measurements.


Grower Tested, Industry Approved


Naturally, when growers first stumbled on the specs for these retail bulbs It seemed a little too good to be true. Once people actually started using them and showing off the difference it made in their plants, ceramic lamps gained a following and the industry began to notice. We can talk PAR, spectrum and PPFD all day. And yes LEC lamps do excel in those areas, but perhaps more compelling is the fact that this tech was discovered “in the field” by growers just like you. It has been researched and vetted not in labs but in garages, basements and warehouses. This is a product that pushed its way into the market and onto grow room shelves as a response to consumer demand.


The Other Bits and Pieces


We’ve been focused mainly on the lamp since most of the LEC fixtures on the market will use either one or two 315watt bulbs. Even considering the improved spectrum, it may not seem like a small wattage bulb could keep up with fixtures pulling nearly twice the power as many growers had been claiming. The ballasts that drive the new lamps are also much improved over the standard magnetic coil ballasts that are used with most metal halide lamps. Just like DE fixtures, the digital ballasts which drive the new LEC lamps use new “digital square wave technology” which basically means the ballast spends more of its time at maximum voltage/light output.


The lower wattage draw means less heat to dissipate even though the lamp element itself is at a higher temperature. This allows the new LEC fixtures to be run open without a lens, keeping the bulb at optimum temperature (and therefore spectrum) without a heavy glass lens, which can rob 10% or more of light output. So now we know it’s a combination of the wide spectrum lamp, efficient ballast and ideal reflector design that allows these fixtures to perform so well compared to lamps drawing much more power.


Applications Well Suited for LEC


While there are both bloom (3100k) and veg (4200k) spectrum LEC bulbs available, either bulb is really dual purpose. That doesn’t mean they’re the best lamp in all circumstances, though. Despite all of their advantages, the 315w LEC does have a smaller effective footprint compared to a 600w or 1000w HPS. For some gardens that may be just right, like when working with a small space, or limited power overhead. We’ll wrap up with some of our favorite uses of LEC fixtures.lec 315 lighting grow tent


Propagation Station:

A single 315watt LEC fixture can easily replace two, 2’x4’ T5 fixtures in your cloning and propagation area. This provides the ideal mount of light without having to worry about excess heat or having to move the lights, while saving power to boot.


Most Veg Rooms:

Having vegged with everything from CFL’s to T5s to metal halides of every brand and wattage, I can safely say that ceramic fixtures produce the best results that I have ever seen during the vegetative phase. I’m not making any claims about growth rate, I’m simply talking about overall plant health and vigor. You can see it in the size and color of the leaves, how thick the stems are and how much lateral branching there is. LEC lamps are always at the top of the list when it comes to recommending a new lamp for a veg area.


Supplemental Lighting in Bloom:

LEC’s are a great way to give your plants flowering under HPS that little extra something they need to reach maximum potential.


Smaller grows without separate Veg and Bloom:

If you veg in the same area that you flower in, it can be hassle to buy extra bulbs, store them and swap them. The low power consumption and low heat dissipation can also really help when you’re in a tight area or are already running at the limit of your cooling/airflow.


Limited Power availability:

Not every grow area has easy access to a 50 amp sub-panel or dryer hookup. Not all properties can be easily modified or upgraded. If you’re working with older wiring, or a limited number of amps, it may be much more practical to use LECs.


If you have any questions about ceramic lighting, use LEC’s, or have other suggestions on how to utilize them, comment below!














  • proxy server list

    Hi there,I check your blog named “LEC 315 Light Emitting Ceramic Fixture | Way to Grow” regularly.Your writing style is witty, keep it up! And you can look our website about proxy server list.


    How long do the 315w Elite Agro bulbs last? When I ran HPS 1,000w bulbs, i would replace them after 2-3 runs. Ive heard so many different things from people about the life span on the 315w Elite Agro bulbs. Ive heard 2yrs and even 10yrs, which i think is completely far fetched. I dont know what to believe, because i also think that they also very ‘strain dependent’. I have been getting my ‘GRAM PER WATT’ on particular strains, and some strains just dont do so well. ….so is it strain or bulbs when im not hitting my gram per watt…? ive got a lot of 315w sets and replacing all of the bulbs will be pretty expensive, So id just like to know when should i replace the old with new, is it based on Hours Ran, Harvests Completed, or Decrease of Yield…..

  • Ed Schwartz

    Please recommend the perfect LEC lights for my 4 x 8 tent. I need (2) 4 x 4 footprint lights.

  • Eeko

    What would you recommend for vegging to replace two 10,000K 1000watt magnetic MH systems?

  • Ken Scates Jr

    I’ve got my plants in a 3′ × 3′ tent. How close to my ladies can I put much new 315w cml light with the 3100k bulb?


    One of tose CDs thаt ater ɑ few listens the songs ɑre
    jᥙst etched into ʏour memory. If youu aree ⅼike mе, who loves fashion Ьut neveг ays attentin to tҺe mannequins, thіs exhibition is for you.
    Ouг dines aⅼso enjoy romantic anniversary and celebratory dining.

  • Rachael Routzahn

    Hi Michael Pal! Your 315w CMH bulb for flowering will be sufficient if it is the 3100 K spectrum (4200K is for VEG). This will be comparable to about a 600w HPS. To get 1000w HPS comparable results, you will want two 315’s or the dual 630w. Even when using 630 total watts your yields may be slightly reduced in comparison to 1000w HPS, but the quality will increase.

  • Steve Hall

    I have 9 CREE COB CXB3590 LEDs (Mouser Electronics) mounted to 3 boards that are 3′ long x 2′ wide. The boards are joined together along their lengths using piano hinge. The LEDs are placed 3 on a board, with one dead center in each board, and one located precisely 1/2 way between the center LED and the end of each board. With the hinges, I can allow the side boards to hang at any angle from 90 degrees to the floor, out to all the way out to parallel with the floor. I adjust them as the plants grow to allow the light to stay more concentrated when they’re small & to spread out when the plants are larger.

    I chose a spectrum that leans a bit towards the red end, though the light looks like daylight when observed. Each COB utilizes a Mean Well® CEN-100-42, a 42 VDC, 2.28 Amp constant voltage/constant current power supply (Mouser Electronics). While supplies of the same voltage, but with greater current output are available, and can run multiple COB LEDs, there isn’t much of a price savings from using them, so I chose to use a single supply for each LED, & thereby eliminate the possibility of a single power supply failure taking down more than one LED. This keeps the garden well lit, even if there’s a power supply failure.

    I have the power supplies for each of the LED COB units mounted in a large electrical box, and all are fused, both at their 120 VAC inputs and their 38 VDC outputs. Again, having each power supply individually fused at the right amperage, prevents a shorted power supply from tripping the house circuit breaker, which would extinguish all of the lights simultaneously, leaving the plants in the dark. The box also features water proof push button switches on its top, one for each LED power supply. Each switch has an LED indicator light adjacent it, so that one can see which lights are on without entering the garden area. These switches also allow one to turn off the voltage to each LED, so that they can be changed without having to extinguish all the lights, should one fail. They also allow you to save money on electricity in the early stages of growth, as one can turn off the outer lights, moving the seedlings to the center, until they get big enough to need the extra LEDs illuminated.

    There is a cooing fan that is running full time in the box. It draws air in through louvers at the top left side of the box, which have a filter behind them, and the air exits the box through louvers at the bottom right. The system uses two 18 conductor cables, easily acquired from Amazon for car stereo wiring, that connect via Canon style connectors (also from Amazon) to the electrical box. They then run up and over a PVC framework that creates a wall of reflective mylar on one side of the crop, and then drop down to the light fixture, connecting there via a single terminal strip. I acquired the box from a surplus outlet. It was originally made for Honeywell and housed a very high capacity UPS computer power backup system & the associated batteries. this was a very expensive box as new, but I got it very cheap. If a good box can’t be located for a reasonable price, one could simply mount the power supplies to a piece of plywood and locate them where ever is convenient.

    The LEDs are mounted to the largest heat sink available for them, and using this heat sink eliminates the need for fan cooling of the LEDs. Round holes of the appropriate size were cut in the main fixture boards. The LED chips are glued to each heat sink, using high thermal transfer epoxy. The heat sinks were then placed on the main boards, with the LED chips in the holes cut for them. Then, 3 long screws were passed through the main boards and up through the heat sink.Then, large diameter washers and nuts were used to hold the heat sinks in place.

    Total output of this system is probably just a bit less than a 1000 Watt HPS, at around 108,000 Lumens. I haven’t even considered trying to figure out stuff like PAR. All I need to know is that this system grows plants extremely fast and develops huge colas at flowering. My electric bill is reasonable, and the room is cool. It does, however, have one big downside. It costs around $1000.00 to build! But, it should last for many years. The cost could be reduced some, if one could make an enclosure to cover the back side of the light fixture. Then, a single fan could cool smaller heat sinks in @ of the 3 chambers, saving on the price of the heart sinks (which are pricey!) and using only 3 reasonably priced fans, one for each main board. Not for the faint of heart, but if you have some skills and do your research, maybe you can build one, too. I love mine!

  • I Like Big Bulbs & I Cannot Lie | Hydroponic and Organic Gardening

    […] For more on CMH lighting technology check this out LEC 315: Ceramic Metal Halide Technology. […]

  • Michael Pal

    Is a 315w CMH Mastere Color bulb good enough for flowering or am I going to be disappointed?

  • Temperature & Your Grow 101 | Way to Grow

    […] for you to mitigate your heat issues this simply, you may want to consider making the switch to ceramic metal halide fixtures to lower your heat […]

  • Write a Comment

    Your email address will not be published. Required fields are marked *