Mh Bulb In Hps Ballast

Discussion in 'Growing Marijuana Indoors' started by gonejah17, Aug 15, 2007.

  1. I know I know I know, but is EVERYONE ABSOLUTLEY SURE that you CANNOT use a 400WMH blub with a 400WHPS ballast?!?!? Cuz Ive seen it over and over that u NEED the MH conversion, but Ive also seen here and there that using an equal watt MH bulb WILL work in an HPS ballast. is this wrong??? are u SURE??? POSITIVE!?!?!?!? what will happen if I try it and it doesnt work??? just wont light up or will it blow the bulb???? or will it damage the ballast/socket?????? any help would be greatly appreciated. heres a little quote from something I read on the issue . . . .

    You can run
    1) either mh or hps light through both stages of growth (good).
    2) run a mh light through the veg phase of growth followed by hps light through flowering (very good).
    3) run both mh and hps light through all phases of growth (best).
    I've found either a single metal halide or high pressure sodium light system works nearly as good as a dual system. So if you only have one or the other don't worry, it will work just fine. You can't use a standard hps bulb in a mh fixture, but you can use a mh bulb in a hps fixture of the same wattage. I didn't think this was possible till several months ago when someone I trust told me it was possible. So I decided to try using a 400 watt mh bulb in a 400 watt hps fixture. The plants are growing as well as they did under the mh bulb in a mh fixture. The bulb hasn't had to be replaced and the ballast runs as cool as it does with a hps bulb. When I want to use the hps bulb, I simply remove the mh bulb and replace it with a hps bulb. So if you can only afford or only want a single fixture, I recommend getting a hps fixture and standard mh and hps bulbs rated for the same wattage as your light fixture. Use the mh bulb for veg growth and the hps for flowering. There are hps bulbs that can be used in a mh fixture and vice-versa. But these are special bulbs and cost about double the price of a standard bulb. Bear in mind, you can only use a bulb of the wattage you light system was designed for. A 400 watt system only uses 400 watt bulbs. Don't use any other wattage than the one listed on the ballast of your light system. One exception would be a 430 watt bulb designed for a 400 watt system. There will also be a lamp type specified on you light system (probably on the ballast itself). My 400 watt metal halide setup specifies an M59/H33 lamp type. M59/H33 is an ANSI (American National Standards Institute) ballast rating. M59 is a 400 watt metal halide ballast. H33 is a 400 watt mercury vapor ballast. So my light fixture could run a 400 watt metal halide or 400 watt mercury vapor bulb. 400 watts is about the best size of light for growing hydroponic marijuana in a personal garden. You should be able to grow 4 to 12 plants at a time. 250 watts should be good enough for up to about 2 to 6 plants. Anything larger (the next standard size is 1000 watts) and you are going to draw a lot of electricity. Anything smaller will limit the size of your garden to one or two plants, unless you can supplement it with strong sunlight. Expect to pay $150.00 to $500.00 for a 100 to 1000 watt lighting system. You can get a 400 watt gym type (high-bay or low-bay) light (hps or mh) for about $150.00. While a 400 watt Son-Agro, or other high end grow light system will cost $300.00 or more. I use a 400 watt metal halide gym type light (high bay) on an 11 plant garden, it works fine with 6 to 10 plants. I usually grow 3 to 6 medium size (18 inches) plants at a time. If you can afford a lighting system made for horticultural purposes with a good reflector and ballast, get it. It will last longer, allow the light to cover a larger area (more plants), and increase the amount of light individual plants get. You can also find some high-end dual (hps and mh) fixtures. These dual systems can provide both mh and hps light through both growth phases. You might want to consider one of these, if you haven't already bought your lighting source yet. If you can't afford better, a high-bay or low-bay type light will work fine. I use one. The best source I have found for buying lighting fixtures, bulbs, and other hydroponic equipment at very good prices is eBay. There is lots of competition and selection.

    Is this guy full of ish?????
  2. i know this is old as hell but i have the same question.. just did a search and found this dead unanswered thread
  3. i have no experience with those lights, im a CFL man, but its better to be safe than sorry. I wouldnt risk the danger of trying to put the MH in an HPS socket, unless somebody with EXPERIENCE on this website has actual proof that it can work(not some new guy who claims he does it all the time)
  4. No they can't be mixed

    HPS bulbs need completely different chokes to MH bulbs

    that's why you have to buy separate ballasts

    although there is a new combi bulb on the market that you can use in an HPS ballast

  5. I agree, they won't work. Just pick up a mh conversion bulb. They're around $50-60 at htg and all over the internet.
  6. If you disconnect the ignitor, you can get an MH bulb to work. The ballast won't be providing the required wavelength that an MH bulb specifies, but it will still light up.


    I believe that 1000W bulbs have the most similar wavelength requirements, therefore those are probably the safest to do this on. Also, I would only try this method on a cheap Home Depot bulb. It doesn't make sense to do this with a specialized grow bulb, since those bulbs cost as much as a ballast anyway.
  7. You need to buy one of these MH Conversion Bulb.

    You cannot ignite a MH bulb w/ a HPS ballast.

    They have opposite conversions as well HPS Conversion Bulb The 360W HPS Conv. Works on a 400W MH ballast.
  8. You know...I know where I can get a street light...Can I wire it 110v and plug it in?

  9. dude, are you being serious??
  10. #11 shafro, Mar 30, 2009
    Last edited by a moderator: Mar 30, 2009
    I run a 320 watt multi-vapor MH in a 400 Hps ballast
  11. As a matter of fact, I am. I have heard of something similar before with a HPS light that was 220v. It takes longer to warm up, but once lit, it was the same as when it was 220v. Only difference was that it cost more to run.

  12. Let me clarify you can run a MH bulb in an HPS ballast (same wattage of course) But not the other way around. A HPS bulb will NOT fire in a MH ballast.
    -HPS bulbs use an igniter to light whereas MH bulbs dont. HPS ballasts are built with the igniter & MH ballasts are not. HPS bulbs wont fire in an MH ballast because it has no ignoter. Conversion bulbs are necessary for the MH ballasts to run HPS bulbs. Hope this helps guys lmk if u have questions. I have worked at a hydro shop for over 7 years & know this because of experience.
  13. i wanted to know can i put a 150 watt high pressure sodium bulb in a 150 watt CFL socket to grow been looking up sockets and fixtures for HPS and to expensive
  14. Nope... two very different beasts. Long story short (you can read "why" in a number of places) that's why there's different (and more-expensive) equipment, for the better bulbs :)
  15. does anyone knows where i can get some good seeds i live in the U.S and its hard to find some good strains any advice?
  16. If I put a converter bulb in my MH HID light thereby changing it to HPS would I get the energy efficiency HPS systems are supposed to have?
  17. i never tried it. but if it powers on and don't shorts out and the bulb don't look dim your good it should power fine and do the job
  18. Well in my own experience (right now) My ballast runs both 400w HPS and 400w MH. The website that i bought it from says it was switchable, the ballast itself does not, but i promise you it does.
  19. YOU CAN USE AN MH BULB IN AN HPS BALLAST BUT NOT VICE VERSA! PERIOD. ITS BEEN DONE AND IT WORKS... THE ONLY problem with using it is that the MH's bulb life is compromised by VERY LITTLE! IF ANY AT ALL, WITH A QUALITY BULB!!! (Phillips ;) )

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