# Running mh and hps consecutively



## The Grinch (Sep 26, 2009)

G'day

I've read that ultimately a grower should use 3:1 mh:hps for veg and 3:1 hps:mh for flower.
Could you achieve the same thing by running a light for 3 days on mh then 1 day with hps for veg?

Cheers
Grinch


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## Redeflect (Sep 26, 2009)

For the most part yes, but there are better ways to time it based on the plant's priorities. For instance in the last week or 2 of plant flowering, the plant focuses less on stretching and more on resin production. This is why for the last week or 2 of flowering, many people like to switch their HPS for Metal Halide. Yield is reduced only slightly but resin production is increased by a good deal. In general, it's good to use both blue and red spectrum lights, but you always want to emphasize a spectrum at a time the plant uses it the most, rather than in a set proportion.


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## cerberus (Sep 26, 2009)

Redeflect said:


> For the most part yes, but there are better ways to time it based on the plant's priorities. For instance in the last week or 2 of plant flowering, the plant focuses less on stretching and more on resin production. This is why for the last week or 2 of flowering, many people like to switch their HPS for Metal Halide. Yield is reduced only slightly but resin production is increased by a good deal. In general, it's good to use both blue and red spectrum lights, but you always want to emphasize a spectrum at a time the plant uses it the most, rather than in a set proportion.


could you give some more details on this? I am looking at running dual 400's on MH and one HPS concurrently, with the MH over the newest flowering plants (for say 4-5 weeks) and the HPS on the other half of the room for the last 4-5 weeks. I would love some more info on this.


p.s. I hope I am not thread jacking here.


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## Redeflect (Sep 26, 2009)

The plants in veg closer to the HPS would probably stretch more (not just because they are farther from the HPS). The plants in flower closer to the Metal Halide would have more resin and probably be a little bulkier. In general all the plants would benefit from the mixed spectrum. However, if you're growing just as many plants from fem seeds or clones as you're going to flower then you might as well use a smaller Metal Halide because the plants will be smaller so you can keep them in smaller containers and use a smaller light. However, if you're using unfeminine seeds than I'd suggest using the same wattage MH with 2x as many plants in smaller pots. Once you identify the sex, you'll be getting rid of about half, and then you can put them in larger containers under the HPS.


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## The Grinch (Sep 26, 2009)

thanks for the help guys.

redeflect, I have a 400w electronic ballast and am growing 1 plant under it. I am growing for quality not yield so extra resin would be awesome, so thanks for the tip for changing to a mh for last 2 weeks of flower.

do you have other examples of how to time changes to optimise my grow.

Thanks Grinch


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## Redeflect (Sep 26, 2009)

The switch to metal halide at the end of flowering is new to me, I only recently learned of it (but it isn't disputed). The only other things I can think of, are already pretty well known... 2 days of darkness at start of flowering to "jump-start" flowering. Flower nutrients 1 week after flowering cycle begins... nothing that most people don't already suggest. Using blue lighting at the end of the flowering phase makes sense, I just never thought of it until I read about it recently. Most people want yield rather than quality, and that is why it isn't mentioned often.


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## cerberus (Sep 26, 2009)

It all seems to be fairly logical and not so crazy. I am thinking of running the 800 watts (2x400's MH & HPS) in the same room at the same time. I don't know how the 50/50 mix could be bad, MAYBE a bit of an over kill on the MH but what the hell. Thanks for the knowledge Redeflect.


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## LogHead (Sep 26, 2009)

i posted the same thread a few weeks ago. it would be a great idea. no it wouldn't be overkill either their is no such thing as overkill on light. you just have to try extra hard to keep the temps down. the ONLY dispute i really see is that 600w lights would be better lumens/watt ratio and thats if you want to be 100% efficient +more for yield. so what you lose in one spot slightly(yield) you gain in another(extra bag appeal, potency, resinous).i have seen plenty of people mix spectrums for cfls and get some great looking stuff. yield was not high bc they were just cfls but this is exactly like doing that but with much more powerful light(so yields will be better). so running the mh during flowering is suppose to help because uvb slowly kills the plant(not enough to notice) so the plant reacts ie starts producing more resin to protect itself. plus the mh promotes bushy growth and that will be good in flowering to prevent streching. then you add the hps in there and that gives it the light it is actually craving for (more like 3000k spectrum) so it throws you more bud. so you do the math my friend mh +hps=

Loghead


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## DaveTheNewbie (Sep 27, 2009)

i always was told that in flower the trick is a 600 HPS and a 400 MH at the same time


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## cerberus (Sep 27, 2009)

Thanks for the good answer Loghead, I was thinking the same thing. I had not heard of the 600/400 ration but obviously that gives you 1k 200 more watts. These 400's where gifts, so the 600 is out.

thanks and sorry for the thread hijack. my bad


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## cannibus corps (Sep 30, 2009)

im currently running 2 400w mh and 1 1000w hps over 30 plants not sure how it will effect but will post pics in a few weeks


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## Brick Top (Sep 30, 2009)

DaveTheNewbie said:


> i always was told that in flower the trick is a 600 HPS and a 400 MH at the same time


 

There you have the dual-arc bulb, a single 1000-watt bulb that burns 600-watts producing HPS and the other 400-watts producing MH.


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## cerberus (Oct 1, 2009)

bricktop,

do tell. What kind of ballast runs that? I have never heard of such a thing


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## LogHead (Oct 1, 2009)

i think the hybrid bulbs could just run on remote or digi but i'm not sure. i'm not sure someone correct me if i'm wrong here


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## Brick Top (Oct 1, 2009)

cerberus said:


> bricktop,
> 
> do tell. What kind of ballast runs that? I have never heard of such a thing


 
I am very sure there is a great deal you have never heard of. 



[FONT=Arial, Helvetica, sans-serif][SIZE=+1]PlantMax Dual Arc Bulb - HPS + MH 1000 Watt[/SIZE][/FONT]




[FONT=Arial, Helvetica, sans-serif][SIZE=-1]*
600w HPS & 400w MH In One Bulb*[/SIZE][/FONT][FONT=Arial, Helvetica, sans-serif][SIZE=-1]
The PlantMax Dual Arc Bulb incorporates the best of HPS and MH in one bulb with two simultaneously operating arc tubes that are optimized for peak performance. The 1000 Watt Dual Arc Tube Lamp runs a 400w Metal Halide and 600w HPS in one bulb providing full spectrum lighting for your plants. This PlantMax grow bulb runs on a 1000w HPS ballast and emits 110,000 Lumens. 
[/SIZE][/FONT][SIZE=-1]*Dual Arc bulb shown operating in a reflector at left.*[/SIZE][SIZE=+1] *Price:* *$89* [/SIZE] * qty:*​


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## Brick Top (Oct 1, 2009)

*Plantmax 1000w Dual Arc Tube Bulb*

The Plantmax 1000w Dual Arc Tube Bulb is the next progressive step in horticultural lighting. Product Code: Plant1000w
Price:$89.95


Qty: 
Qty must contain a number between 1 to 9999Qty must contain a number between 1 to 9999








​ 
Click here for larger view​ 





Description 
The Plantmax 1000w Dual Arc Tube Bulb is the next progressive step in horticultural lighting. The bulb incorporates both a 400 watt Metal Halide arc tube and a 600 watt High Pressure Sodium arc tube in a single lamp giving the grower the most balanced light spectrum available from any bulb. With an initial output of 110,000 Lumens, this bulb is easily a match for any H.P.S. bulb on the market. If you would like to maximize the potential of your plants, this is the bulb for you! *The bulb is designed to work in a 1000 watt H.P.S. ballast.* 

This bulb works with Hydrofarm and Sunlight Supply ballasts.



http://www.hydroasis.com/hy/productdetail.aspx?id=1864&product=plantmax-1000w-dual-arc-tube-bulb


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## The Grinch (Oct 7, 2009)

Hey cerberus - did you go with the 400w hps + 400w mh?
Are you moving the plants around (or globes)?

Are you planning on running the mh/hps combo through veg as well, or doing 2 mh?


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## cerberus (Oct 8, 2009)

The Grinch said:


> Hey cerberus - did you go with the 400w hps + 400w mh?
> Are you moving the plants around (or globes)?
> 
> Are you planning on running the mh/hps combo through veg as well, or doing 2 mh?


I have one 400 MH + 100MH (side lighting) for my veg. I am using the 400MH & HPS for the flowers simultaneously, I have decided on running to sections of flowers. The MH and HPS are right next to each other in a space about 3'x3.5' (literally the hoods touch). The first set (4-5 plants) will be under the MH for 3-4 weeks, and then move under the HPS. Then a second round of flowers will be brought under the MH, again for about 3-4 weeks. finally the two will rotate putting the second crop under the HPS and the first under the MH for the last 1-2 weeks, when I will cut them and start the third round. 
It was a debate between having two sub-sections in the flowering room (2 packs of 4-5) or one large group (9-10) but ultimately I went with the semi-perpetual setup.
I want to post some pix, but my paranoia is always high and it just seems iffy to me.. <shrug> 
I don't mind the tin-foil hat.

Have you figured out your set-up yet?


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## The Grinch (Oct 8, 2009)

Kinda..

Was originally gonna have 2 tubes in my little area, each with a 400 so i could have 2 independent grows going. But laziness won out, so i'm just gonna have both lights going at same time, and put 3 plants under them, each scrogged across the entire area. gonna have 1 400 hps, and 1 400 mh going at same time for flower, and change them around twice a week - gonna be in there for scrogging, so shouldn't be to much extra work.
I want to have the options of 6 different strains, so trying to decide between making a mother and grafting on to her and taking clones as I need, or having the 3 plants with a 2nd strain of equivalent nute and flower times grafted on, and then reveg.


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## cerberus (Oct 8, 2009)

The Grinch said:


> Kinda..
> 
> Was originally gonna have 2 tubes in my little area, each with a 400 so i could have 2 independent grows going. But laziness won out, so i'm just gonna have both lights going at same time, and put 3 plants under them, each scrogged across the entire area. gonna have 1 400 hps, and 1 400 mh going at same time for flower, and change them around twice a week - gonna be in there for scrogging, so shouldn't be to much extra work.
> I want to have the options of 6 different strains, so trying to decide between making a mother and grafting on to her and taking clones as I need, or having the 3 plants with a 2nd strain of equivalent nute and flower times grafted on, and then reveg.


I can dig that. sounds like we where mulling over the same things. We should keep conected to see how things turn out.


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