Do u perfer mh over his? I always just use hps
This is my newb opinion I started May of this year.
On the HID side, despite the data sheet Nazi's and their babble over inefficiency, what is everything always compared to a 1K HPS, A Gavita, etc, etc. A lot more lately the DE 1K lights. I am currently running a 1K HPS on half my tent and 600W of COB's on the other. The plants under the COB are okay (except for a sick plant that will be taken out tomorrow most likely and was a rehab project no fault of the light) BUT, it seems so far at the early stages the plants under the HPS start off quicker and the texture to the leaves is more "natural" feeling, I really do not know how to explain this it just has to be seen and felt in person. That said I have a 50" tall Sativa right now blowing up under the COB's which does not disappoint me either. We will see how this run turns out.
Still on the HID side of things, to me (and many others) you can't beat the Blue MH from Hortilux for veg and they make one in all kinds of watts. Many experienced guys have started to run the blue bulbs straight through as you will sacrifice a small amount of yield but gain the losses in better quality weed.
For me the CMH fits in here. Whereas most think because the MH in the name that they're just for veg and that's far from the truth.
My CMH only ran 5 degrees warmer in my 3x3 than the 4 COB LED it replaced. To me that's nothing level playing field. The quality of the the plants under the CMH were just like what I have seen under the MH/HPS, now I am talking plant texture, structure, growth etc, I am not talking yield. I am NOT saying (1) CMH = a 1K or anything like that just to be clear here lol.
To me the CMH is a middle ground where you get what I consider better lighting because of the UV/IR in the spectrum vs the COB only lights. But There's pluses and minuses to both. And right now my current run and some PAR testing I am waiting to see will determine where I end up but I am leaning towards the CMH for my grow because I cannot currently DIY again and prebuilt COB is not cheap.
So for me it will be simple. Run the same strain under the COB and 315 and see what happens. If let's say the CMH yields 20% less but cost 40% less to buy and uses about the same electricity then that's a no brainer. Numbers do not lie.
Not all gardens are the same and control of the growing environment is paramount over source of light. What most newcomers don't get, is that the really good growers can grow a plant with just about any light, and they use for a grow whatever fits the situation better not necessarily their favorite light etc. You need to adapt to your situation. I can tell you COB's are the end all be all and grow a stupid amount of weight under X amount of light, but if you live on the opposite side of the country from me and get freezing temps my grow where it's 78 outside in Dec doesn't mean shit to you, understand?
That's why I try to tell people so they don't get caught up in all the light BS like I did. Research, sit back, get a good quality light, and when you can hit 1GPM with whatever light you have, then see what else can be improved in your grow, nutes, medium, add in CO2, automated controllers for lights, watering, then see if a new lighting technology will help you, and you will at least know when shit goes south, it's the changes and not your abilities.
Sorry for the rant and Cheers
