Looking for input about LED vs MH vs CMH in Vege with some limitations


Planning a new vege room in our facility and have some internal debates on lights and wanna get some outside input. I am not here to debate growing methods, soil vs hydro, organic vs synthetic.

I want to keep focus around lights and their unique benefits such as:

-Growth Speed
-Growth Structure (We will be training, tying, focusing on bushing them out to prep for raised bed with trellis)

In our Vege room we will have a two tier table.

Vege Cycle:

Week 1: Cut Clones
Week 3: Transfer to 1 gallon
Week 5: Transfer to 3 gallon
Week 9: Transfer to 7 gallon
Week 13: Transfer to Bloom (Raised Beds)

We plan on having these LED T5 for this entire room and cycle above.

From Week 0 - 9, we are very confident these LED lights will provide amazing spectrum, penetration, and light for plants at this age and size.

The debate is from Week 9-13 in a 7 gallon, the concern of penetration and strength to get these plants to 36in by the 13th week with a stacked bushy structure (while being trained/topped/tied down)

IF we find that these LED T5 can’t just quite get the plant tall enough or big enough, this could affect planned yield. So alternatives to increase that would be MH vs CMH vs Stronger LED

Here are my thoughts so far:

Stronger LED:

This guy will continue the benefits of low amps, strong light, penetration, and broad spectrum.

Metal Halide:
This is the typical use case for my story above and is the main debate whether we move to this for the 7gallons should the LED T5 not work OR the debate between this and the stronger LED G2 above.

Ceramic Metal Halide:
This is pretty much the best standard now a days for vege, our issue is our height limitations in this room. If the plant is reaching 36in, we will have about 18-21inches of space between canopy and light and that is pushing it for the heat signature of these lights which could cause burn. Especially with Duals.

So that takes us to the final scenarios and the input I am looking for:

1.) These LED T5s will do just fine getting us to 36in with a stacked bushy plant (with training)
2.) They are not strong enough and simply swap out with the G2 which is stronger and has the LED benefits
3.) Metal Halide, using more power, more amps, the hoods are bigger but 18-20 inches typically is ok for the heat signature with these.

But OF these scenarios, which one is BEST for vege growth speed and getting a dope 36in stacked bushy plant for raised bed trellis (screen of green) growing.

Hope I did not dive too deep, any input would be appreciated, just want to hear others thoughts.


This does not address you question but, all the transfers from clone to 1 gal to 3 gal to 7 gal to raised beds is too much labor and if not almost root bound they will fall apart while transferring.
Clone for 3-4 weeks transfer to 4” pots for 2 weeks then straight to 3 gal or 7 gal. Transferring a 7 gal to raised beds will be difficult at best. All this labor will be expensive and get old very quick.
If not renewing raised bed soil invest in a soil steamer.


I agree with @jimdtidrick with the number of transplants posing a problem. Can you tell me a little bit more about the grow? Is the light level increasing at each transplant? What are the room dimensions and plant counts?

My next question would be do you know your current PPFD levels in veg and flower? Cannabis can handle a lot of light, but then your next limiting factors need to be adjusted along with the increased light levels. Watering and feeding will definitely need to be adjusted for faster growing plants.

In regards to spectrum, you definitely want something on the cooler, bluer end of the spectrum. A perfect spectrum is a lot less important than how much light the plants are getting.

I’d only be considering CMH or LED as a lighting investment. You can use either for full cycle growing, and tune spectrum if you need. CHM are a really easy transition for HPS and MH growers, and are a lower investment upfront. LED are going to be the future of agriculture with electric light. Pick a fixture that will last long (passive cooling, glass lenses, dust and waterproof) and fits into your budget and hold onto it. The technology will keep getting cheaper and better, so spec the best for your budget today and try not to swear too much when the same tech costs half as much as you paid 3 years ago.


Check out our LEDs at PowerTrakGrow.com…, Our lights are reasonably priced and Spectrum can be varied according to β€œwhat” you are attempting to grow. We have the recipe and the right lights to make you successful. T LMK if I can help you. Tom Mihalko 401-524-6551, [email protected]

Hey Tom it is great to see your lights provide for the Emerson effect. Too many light companies do not.

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