MH vs HPS - The winner is....

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BBFan

Days of Wine and....Roses
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Well, I made the decision to switch to hps for the remainder of my grow. Hands down winner is the HPS. :eek: The plants under the HPS have really taken off over the last few days.

As Bombbudpuffa pointed out in my other thread, on a watt for watt basis there's no comparison based simply on the math that the HPS puts out about 50% more lumens than the MH. My next test will have to be a lumen by lumen comparison, based on spectral output.

I'll put up some pics this evening when the lights come back on. My apologies to anyone and everyone I've ever challenged regarding the difference between the two. On a watt by watt comparison, IMHO there's simply no contest.

Peace! :cool:
 
So here's the pics of the side by side grow. They're both clones from the same mom taken on 9/5.

On 9/15 I put the one on the left under 400w MH and the one on the right under a 360w HPS conversion bulb. I switched to 12/12 on 9/30, so this is a little more than 2 weeks since the switch.

As you can see, the MH plant hasn't filled out nearly as much as the HPS. So, IMHO, if you're comparing 400w of MH to 400w of HPS- the results speak for themselves.
 
very cool results thanks for the info.
 
Good job! My money was on the hps :hubba: but not for any reason except it's all I use :)
 
Nice test. But I was wondering what the spacing is between the internodes and is their a difference between the two?
 
ooooh, great question!!!! just because they don't work as well in flowering doesn't mean they still can't be better than the hps for vegging.... the internode length will determine that.... lol i took 3 hits today. i don't even know what i'm typing lol i can't tell if it makes sense or not.... damn i'm hiiiiigh.
 
My next test will have to be a lumen by lumen comparison, based on spectral output.

A couple of things about the watt for watt test. I totally agree that HPS beats the MH. but mention of new CMH bulbs and different styles of growing as well as strain type will show different results than just a single grow.
Many hard core sativa dom organic growers swear by MH over HPS but only for that style of growing. Look up -REv AKA rollanterroy. He used to MH veg and first 2/3 of flower then blast with an HPS...but has since switched to CMH with a more complete spectral output and has boxed up his HPS. Worth a look see.
I spectrum and sativas have been pounded in my head. Some SA equatorials only have that blueish spectrum all year round just to name a few enviro variables. I think HPS and MH have a place in the grow and the absolute best scenerio would be both an MH and HPS all through flower giving as much overall spectrum as possible would be the best route.
 
Well from everything i have ever heard, its best to use MH for veg then switch to HPS for flower.:)
 
pcduck said:
Nice test. But I was wondering what the spacing is between the internodes and is their a difference between the two?

Hey PCDuck-

That's a great question. Early on, I was patting myself on the back, because the MH growth appeared much tighter. I have to admit I really wanted the mh to come out ahead- I had predetermined (in my own mind- and that's a scary place:eek: ) that mh is better based on what I've read. I was doing this to prove myself right- oops!

I'm a big believer in MH- one need only look at the spectral output of the mh compared to the action and absorbtion rates of photosynthesis and you can see that the mh puts out way more usable light than the hps- here's the chart:

The hps appeared to have caught up in the stretch, but I'll get exact measurements of the spacing tonight when lights are back on.
 
Mutt said:
A couple of things about the watt for watt test. I totally agree that HPS beats the MH. but mention of new CMH bulbs and different styles of growing as well as strain type will show different results than just a single grow.
Many hard core sativa dom organic growers swear by MH over HPS but only for that style of growing. Look up -REv AKA rollanterroy. He used to MH veg and first 2/3 of flower then blast with an HPS...but has since switched to CMH with a more complete spectral output and has boxed up his HPS. Worth a look see.
I spectrum and sativas have been pounded in my head. Some SA equatorials only have that blueish spectrum all year round just to name a few enviro variables. I think HPS and MH have a place in the grow and the absolute best scenerio would be both an MH and HPS all through flower giving as much overall spectrum as possible would be the best route.

Mutt-

Thanks. Actually I couldn't agree more. There is absolutely a place for both and different spectrums excite different aspects of photosynthesis. If I could, I would mix up the lighting. I think my ideal set-up for my space would be 400 watts of HPS and 600 watts of MH.

But, probably like the majority of the members here on MP, I'm a small time grower. I have 2- 400w mh units that I grow under. Many only grow under 1 HID unit.

So if you have a small grow going under a single 400 watt unit (or 600, or 1000, whatever) and can only use 1 bulb- you have to make a choice (unless you can spend the money on the more expensive bulbs). The average 400 watt mh puts out about 35,000 lumens while the average 400 watt hps puts out 50,000 lumens. That's over 40% more lumens!

And the mh I was using was no slouch- a brand new Sunmaster Cool Deluxe with enhanced output (bulb cost me over $100.00). The hps was a standard conversion bulb, putting out the same spectrum as a cheap Lowe's $20.00 HPS (and has gone through 2 grows)- so I was skewing the results in my favor from the beginning. And the hps still outperformed.

IMHO the increased lumens beats out the better spectrum (at least to a point). And I think I'd say that regardless of strain.
 
Can I ask what medium/style of growing you were using? ferts n such too? I use a 400w MH with a few soft white CFL's for the dark spots in grow all vert. Living Organics Method. Been ecstatic about the MH...i got a 1000w switchable but that puppy is too big for my area :p
Great comparison tho. much appreciated :D

edit:
I also notice that i get a more pronounced pheno expression under an MH. But I agree for most application HPS beats out MH.
 
This is the fundamental kind of experiment that helps everyone. Well done.
 
Mutt said:
Can I ask what medium/style of growing you were using? ferts n such too? I use a 400w MH with a few soft white CFL's for the dark spots in grow all vert. Living Organics Method. Been ecstatic about the MH...i got a 1000w switchable but that puppy is too big for my area :p
Great comparison tho. much appreciated :D

edit:
I also notice that i get a more pronounced pheno expression under an MH. But I agree for most application HPS beats out MH.

Hey Mutt-

I'm growing in a mixture of HappyFrog that I add some regular (non-nuted) potting soil, some perlite and peat moss to (just to make it go a little further).

I add a product called biotone, that contains bacteria and mycorrhizae. Then I throw in some molasses to give the microbes something to feed on.

For nutes I'm using Humboldt organics and some bat guano. Used Grow for the first feedings and fed them Bloom on their last feeding.

As I said, these were all clones from the same mom. The strain is blueberry (been generating my own seeds for a while now). The mom was vegged under 1- 400 watt MH with 2 small hps lights for side lighting (I've also been hitting one of the girls with UVB lighting- but that's another story).

On a lumen for lumen basis- I still believe that MH will outperform HPS hands down. And I will do that test soon. But, on a watt for watt comparison, I'm thinking the hps is the better choice.

Thanks for your input.
 
"On a lumen for lumen basis- I still believe that MH will outperform HPS hands down. And I will do that test soon. But, on a watt for watt comparison, I'm thinking the hps is the better choice."

- Well, WATTS are what we pay for, not lumens!
 
leafminer said:
"On a lumen for lumen basis- I still believe that MH will outperform HPS hands down. And I will do that test soon. But, on a watt for watt comparison, I'm thinking the hps is the better choice."

- Well, WATTS are what we pay for, not lumens!

Yeah, you got that right.

But many of us are also looking for that 1 little thing that makes the difference between good and great results.
 
bombbudpuffa said:
Nice comparison grow BB:).

Thanks Bombbudpuffa!

And thanks for pointing out my math error on my other thread about this test. I don't know how I missed it, I must have been stoned!:joint:
 

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