MH vs HPS for flower

Is there big difference between MH and HPS for flower? MH would allow you to see plant problems easier as it’s easy to see plant problems while the plants are green.

Mh is the wrong spectrum for flower. Just turn the dang hps off or wait till lights out to check for issues.

I'm sure you can use it...but it is not ideal.

I've used MH to flower and it worked fine. I did lose some yield compared to HPS but I did see more trich production with MH.

Yes there's a difference in colour spectrum and output, a hps has much more lumens/output, but some people swear they get better quality weed with them.
Plants tend to stretch more with hps than mh ime so I use mh for veg and until the stretch is done in flowering then swap to hps, technically they're dual spectrum but I also use Son T vialox pure hps orange and to my eye there's very little if any difference between them and dual spec like Grolux and Philips son T

I have found CMH to produce better results in both areas. Never going back to mh or hps

I used cmh and veged my first plants on it.. now there in flower under the same light. Had to get another light for some clone and a couple new plants I wanted to keep in veg.. just using a 5ft tube light. Don't even know what to call it, normal light like what you would see in a hall or something. Only 38w but I noticed that the nodes are are way closer together under this light during veg.. the spacing between nodes under the cmh were massive

MSS said:

I have found CMH to produce better results in both areas. Never going back to mh or hps

Click to expand...

Yup I agree. I use cmh and quantum boards now which I think is the best combo I've tried to far.

My issue with CMH was plants finished like 1-2 weeks quicker than HPS.

Quality / resin way better but yield was just not as good. Probably better yield watt for watt but the early finishing thing was strange.

viridi said:

would allow you to see plant problems easier as it’s easy to see plant problems while the plants are green.

Click to expand...

there are correction glasses around, not perfect, as some lamps have slightly altered spectra, but better than without. Plus a protection for your eyes.

My HPS is twice the lumens as my MH. I will flower with HPS and pull them out into natural light.

How many watts do you want to run, and what is your light budget? You can get dirt cheap mh/hps fixtures, pay a bit more for a cmh, or a lot more for an equivalent LED. You can get good results with any of them.

I recently bought x2 (700w)SunPlix CMH fixtures after using MH, Hortri Daylight Blues in 600w as well as leds. .
Leds (especially cobs or HO white) was difficult for me to veg under. I have a habit of using water when I don't have time to mix a feed & white leds were not so friendly. Mh was though so I figured let's put some cmh in there, after never having used it before & spread that 600w out a little.
Best move i could've made for my veg. Especially being the ballasts are remote optionally. So now I could probably use them or some in the summer too. In the winter simply attach the driver back how it comes factory.
I am fairly confident my 900w Bar-8, led can equal or beat a 1200w DE but I took it a step farther & put it up against 4, CMH, 315's. Best spectrum available & equal efficiencies split up into x4, over a 7'x5'8" area. Covering x2 plants. Its being documented in Grow Journals along with x2 other SBS's that include HLG vs. AMARE Tech. All are welcome to stop by.
At this point in time I'd recommend several 315's over hps or mh. You can get commercial kits for $200 but that SunPlix has the best deal i saw when it came to quality/$, service was great & they hooked it up, saving me a few hundo. To light that same area with the highest quality led i could get cost $1500, the X4 , CMH would've been around 1250 i think, then annual bulb changes = bout $350-$400 over x4 lights. Ill be doing the math on electric vs yeild difference if there is any along with lab results to determine whether there will be more CMH or stay all led.
Wattzup is right about output. Maybe not half but significantly less then hps.
My best HPS work was done by Switching 1/2 the room to MH for the last 10 days. That would make 1/2 a cola turn purple + colors & the other half would stay bright green. All while not losing weight & still getting that second growth spurt on some strains via the HPS.

viridi said:

Is there big difference between MH and HPS for flower? MH would allow you to see plant problems easier as it’s easy to see plant problems while the plants are green.

Click to expand...

Method sevens grow room glasses. Makes your plants under HPS look like they are under MH. They make them for LED’s too as well as lens filters for cameras. One of the best investments I’ve made.

chronnie49 said:

Yup I agree. I use cmh and quantum boards now which I think is the best combo I've tried to far.

Click to expand...

I've been running LED CMH combo for about 2years now and saying that it is the best of both worlds and it finally catching on!

Norml56 said:

I've been running LED CMH combo for about 2years now and saying that it is the best of both worlds and it finally catching on!

Click to expand...

Yea its a great combination. I've only finished one run with a 110 watt Alibaba board and 315 cmh but this time im doing two 220 watt boards and two 315 cmh in a 5x5.

chronnie49 said:

I've used MH to flower and it worked fine. I did lose some yield compared to HPS but I did see more trich production with MH.

Click to expand...

many growers believe that HPS will produce higher yeilds but MH OR CMH will produce slightly lower yeilds but better poiency and flavor. recient studies indcate the higher UV and VIOLET may be the cause of this. as a PU MMJ grower that can't sell what I produce. I prefer MH,CMH.or T5s but a commercial for profit grower would make more profit with HPS

chronnie49 said:

Yea its a great combination. I've only finished one run with a 110 watt Alibaba board and 315 cmh but this time im doing two 220 watt boards and two 315 cmh in a 5x5.

Click to expand...

That should kill it! Great spectrum and what I intend to do in the future.

mauricem00 said:

many growers believe that HPS will produce higher yeilds but MH OR CMH will produce slightly lower yeilds but better poiency and flavor. recient studies indcate the higher UV and VIOLET may be the cause of this. as a PU MMJ grower that can't sell what I produce. I prefer MH,CMH.or T5s but a commercial for profit grower would make more profit with HPS

Click to expand...

I’ve read that somewhere about MH producing more potent weed. How much smaller would yield be

You can mix hps and mh, iirc it's 1 mh to two hps.

viridi said:

I’ve read that somewhere about MH producing more potent weed. How much smaller would yield be

Click to expand...

It's a significant drop from HPS.

Traditional MH lights don't have the light range the plant loves for flowering. Inversely, HPS doesn't have the range to veg to the plants full extent.

You can do both jobs with either light but the over all yield does suffer alot.

CMH seems to be the HID future. I'll probably switch out my MH/HPS systems for CMH when I upgrade.