is mh necessary?

Discussion in 'Growing Marijuana Indoors' started by specialk916, Feb 5, 2011.

  1. so im in the market for a new light. i cant afford to but a mh and a hps, would the plants veg ok under a hps for a month? of is it absolutely necessary to get a mh/hps?

    also ive heard that 600w hps gets you the best lumen per watt ratio, and i can place them closer to the plants than a 1000w, if i can get a 1000w for just slightly more should i go for it?
  2. Ill tell youI have 2 rms one is 10x20 with 8 1000s. the other is 5x20 with 4 600s. Big rm 60 plants little 20. The little rm got planted into flower 2 weeks after the one with thowys and there bigger and have more mature buds. So my next room im buying all 600s. I got a 1 ballast 2 light system with the 600s also. cheaper and with some good eye hortilux bulbs they do better then my thowys. go figure.
  3. yes you will be fine, mh is just better cause it has more blue then red, where as opposite for hps which is more red then blue. Ive vegged with both with no problem.
  4. i was leaning towards 600w too. i think thats what ill get unless someone has enough confidence in the 1000w. i trust my fellow gc peers.

    im hoping someone will tell me the veg with hps and its not a big deal

  5. sweet, thanks
  6. While MH is not a nesessity, i does contain more of the correct light spectrum (blue) for the veg stage of a mj plants life. You can easily grow from sprout to harvest with just a HPS. Personally I veg under MH and flower under HPS which contains more red spectrum. Hope this helps. Good luck
  7. i use a 600w hps dule spectrom bulb so you get mh and hps in one bulb look at this video befor you get a bulb it MIGHT just help you make up your mind

    [ame=]YouTube - 1000w vs 600w Trees Yield.mpg[/ame]
  8. You can't afford both?

    Dude you can get one ballast that runs both for about the cost of either ballast that runs just one.
  9. using an HPS when you would ideally be using a MH (during veg) isn't gonna mess anything up but you will at least experience differences in how they grow.

    the plant MIGHT stretch vertically more vegging under an HPS vs MH because it will be lacking in the ideal spectrum whereas with a MH you will experience wider growth.

    but these are minimal differences and i wouldn't worry too much unless you're a perfectionist. you can still grow perfectly healthy plants entirely under HPS
  10. I second the motion for a switchable ballast. Trust me, I have seen first hand the difference between veging under MH and HPS. MH is the way to go for veg. And while you're at it, consider a digital ballast. My NextGen powers both MH and HPS and switches automatically. There is a great bulb out for digital ballasts called a Digilux. They come in both MH and HPS and have enhanced spectrums. Great bulbs.
  11. thanks guys. now im armed with ammo for when i go into my local hydro store. really appreciate it. so im def getting a digital ballast, if they hav a 1000w ill get that, if not ill happily chose a 600w dig over the 1000w coil. and ill compare the price of a switchable to just a hps. ill try to get the switchable but if not ill go for a hps with an enhanced spectrum bulb:) thanks again friends

    what would i do without grasscity?
    o i kno, grow shitty weed...
  12. I am currently vegging with a 400w HPS. I am getting great results. I keep hearing that the plants will be stretchy. I have not experinces that. Here is a couple pics of my plants about 3 weeks into veg. As you can see they are growing fine and not really stretching at all.

    As for wattage. 600w is always better than 400w. But remember to consider heat output. My 400w keeps my daytime temps around 72-78F. If I was using a 600w I think I would run into some heat problems in my small closet. Just something to think about.

    Attached Files:

  13. IMO HPS is BETTER for veg. The spectrum on MH may be better, but that is overshadowed by the fact that HPS is much more efficient than MH and offers much higher lumen output. Personally I have no use for MH at all.

    Definitely get the 1000w if you can. Yes the 600w is more efficient, but you have a lot higher lumen output with the 1000w, period. In that video that guy compared a new MH/HPS hybrid bulb to an HPS that was near the end of its usable life. Not a valid comparison.
  14. #15 mannix, Feb 6, 2011
    Last edited by a moderator: Feb 6, 2011
    lumen output doesn't mean shit whenever its not the right spectrum so its actually no better to use HPS during veg, its just a fact.....otherwise this wouldn't be a question in the first place. another fact is that plants grow bushier and wider vegging under MH as it contains the best spectrum for vegging and HPS vice versa for flowering.

    edit: but don;t get me wrong i am well aware that you can grow from start to finish using HPS and have very successful plants as its done many times.
  15. Actually it does mean shit. NEITHER are the perfect spectrum at all. MH and HPS are both far from perfect when it comes to spectrum. MH is slightly better yes, but HPS is just fine for vegging, (spectrum wise) and the lumen advantage is significant enough to outweigh MH spectrum advantage imo. I get better growth from HPS over MH for vegging.

  16. You are probably the only person on the planet that holds that opinion. I myself have done a side by side comparison and it is indeed a fact that MH is better for veg. It is an inarguable fact. Just because you don't believe it doesn't make it not so.

  17. No I know several really good growers who believe the same. Against popular opinion? Sure, but I go by results not popular opinion.

    This is one guy who does it also. The results speak for themselves.

    [ame=]YouTube - HPS vs MH and RO vs Filtered[/ame]
  18. HPS, all the way through, veg through bloom?... eh, I suppose it can work ;)


    (upper left bud from the above plant)

  19. Fo sho. Well, if it works for you, keep it up! I did a side by comparison of MH V HPS for veg and the MH plant grow twice the size of the HPS plant. I don't know how you get your results, but hell, the results are what matter, right?

    Happy growing!

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