Should i bother with MH?

I have a 400watt digital system
ive used MH then HPS before.
I have new seeds going in from the march promo and wondering
if i should even be using MH
I know that it makes bushier plants etc, but with the lumen output being 33k vs the 55k
Does it affect yeild even, or should i just go from HPS start to finish from now on
most people say that cant really tell a difference, and others say its better with HPS only
and then others say its better to use MH for vegging. but expect to grow a week longer.


Should i even bother with MH from now on?

CFL,, all you need (for now).

Canon said:

CFL,, all you need (for now).

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Not an option, also wasnt in the list of options.
And i was talking about the whole grow duration.
Didnt u read it?

You know what the plants need, and you can hang on to the fact that HPS works all you want, but you still know the answer.
What you decide to do is up to you.

Remember that during veg, the plants are smaller, and the lumen count is not that important to the plants.

In short, yes you should bother with it. But don't take my word, research a little if in doubt.

I think you're confusing "kelvin" with "lumen"...lumen=candlepower, brightness and kelvin=color temperature.
What's important about a MH bulb is that it is at least 4,000K and sometimes pushing even 6,500K, promoting healthy veg. growth. Since the switch to flowering not only has to do with light cycles but also the change to a much lower color temp (2,200-2,500K), I can only naturally assume that the HPS would be best as a flowering only bulb. I had great results with my MH, rapid rapid growth. Hope this helps

well, having grown from seed with a 600w hps and a 400w mh.

id pick the hps any day. (though we are talking 3 times the lumens)the mh plants are sorta prettier. but the hps grows them much stronger and faster, bigger leaves.
especially if grown straight from seed. seedlings just take off, much faster than any cfl and creating much more strong and robust plants.

the best growth ive seen is with mh and hps combined (im trying out adding t5 to that now, it makes an interesting change, with the hps alone, late autumn evening light, with the mh added, it looks like late afternoon sun, with the t5 added it looks like high noon in the tropics there)

though, it isnt dramatically better, the leaves just get more elongated at the beginning and bigger later and look better, along with a somewhat speedier growth, the look is more natural, more so than even the mh.

i use the mh as sidelighting, 400w to a 600w hps.

and if it wasnt so cold outside and needed more fans and if i payed alot for electricity.

i wouldnt, its not that much better.

usually the mh bulbs are twice as expensive around here, so despite making prettier plants, i find it not worth it, especially since the hps makes stronger stems (very good for later buds) and bigger leaves (excellent for later buds)

maybe somewhat stretchier but the strength of the plant makes up for it.

naturally and of course this is just a personal preference, another might find the qualities of mhvegged plants to suit him better, but it sounds more like to me, that you are of the same opinion as i and just wanted confirmation from a more experienced grower.

Just get a hortilux bulb which has more blue in it and you can use it all the way thru veg to flower.I use mh conversion right now since i have it but i have done grows with just hps and i like the results with i do notice when my nodes are closer together using the mh for veg and switching to hps for flower i get a long cola but no matter what i still get big colas with just hps

There's always the dual arc option for using one bulb all the way thru...

According to Ed Rosenthal, you can do entire grows with HPS, MH is not needed. In fact, recommends HPS. If you want to know the reasoning behind it, google Ask ED HPS vs MH

Of course you can do a whole grow with HPS. That is not the issue here.
The OP had the option to use MH, so why not?

I've never heard someone say that a 2700K HPS-bulb is better than MH-bulb during the veg.-stage.

Also, blue light give you a higher female to male ratio (this might be a myth, but there are a few articles stating this).

However, HPS (2700K) is good for germination and root-growth. It will also make your plants taller (but who wants that?).

Serapis: Why did he say HPS is best for veg? It's the first time I've heard this.
Edit: Serapis, I'm sorry but I don't respond well to "google it" in this case, as the statement goes against forum-wisdom (or myth, I'm always open to new things). Which means I think you should share your knowlegde in this case (with scientific or common-sense reasoning, not just opinions).

krok said:

Of course you can do a whole grow with HPS. That is not the issue here.
The OP had the option to use MH, so why not?

I've never heard someone say that a 2700K HPS-bulb is better than MH-bulb during the veg.-stage.

Also, blue light give you a higher female to male ratio (this might be a myth, but there are a few articles stating this).

However, HPS (2700K) is good for germination and root-growth. It will also make your plants taller (but who wants that?).

Serapis: Why did he say HPS is best for veg? It's the first time I've heard this.

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total myth..I got 3 males out of 5 reg seeds under a mh bulb

Since when do HID bulbs under the high pressure sodium label come designated as 2700k? Sounds more like you are talking about CFL bulbs than HID. Also, there is no scientific proof that MH bulbs give a higher female to male ratio, regardless of where you read it, it goes against the law of nature and botany.

As I said, if you question my post, go ask Ed in google.... you know who Ed Rosenthal is don't you? Author of several MJ growing guides and books.

krok said:

Of course you can do a whole grow with HPS. That is not the issue here.
The OP had the option to use MH, so why not?

I've never heard someone say that a 2700K HPS-bulb is better than MH-bulb during the veg.-stage.

Also, blue light give you a higher female to male ratio (this might be a myth, but there are a few articles stating this).

However, HPS (2700K) is good for germination and root-growth. It will also make your plants taller (but who wants that?).

Serapis: Why did he say HPS is best for veg? It's the first time I've heard this.

Click to expand...

Why so hostile, serapis? All I want to know is the answer to why HPS is *BETTER* than MH in veg. This is what *YOU* claim not this Ed guy. This is what *YOU* have to explain.

And why I say 2700K? Well, there is this thing called dual spectrum HPS. And when people say HPS they do not mean HPS with extra blue, so I simply wanted people to understand I'm talking about stock standard good old HPS.

well i tried an experiment, and if anyone would like some pics i can show you, just have to wait until the lights come back on. i tried starting seeds under a T5 floro veg specrum light, and i also put one of the cups in my 400watt MH veg room just to see what would happen. even with the top of the plants being less than 1inch away from the t5 at all times the plants still seemed to stretch. BUT! =D seedling i started under the MH is almost 2ft away from the bulb and its still tight as shit no stretch at all.

hope the info on this lil experiment helps! be positive and love your life- 311

i use a 250 MH to veg as i like the tight nodes and little stretch as mentioned in the post above. theres no reason why u couldn't use a dual spectrum bulb as mentioned as well with good results. theres no right or wrong way just depends on ur style

good luck bro

I grow under HPS and CMH bulbs and never use MH. There's been nothing wrong with my plants or yields. As for MH bulbs causing the plants to get bushier, I can't imagine a bushier plant than my pineapple chunk, which gave me 3 ounces of dried bud. All of my plants; white widow, raw diesel, super skunk, and pineapple chunk did very nicely under HPS and CMH bulbs. CMH = Ceramic Metal Halide.