I was watering my plants when I noticed my metal-halide (MH) bulb flicker a little bit. It seemed to flicker as I made the every-so-softest bump on the floor as I placed a plant down - but I'm not sure if that was a coincidence. A few minutes later, it flickered even more (again, seemingly because of a super-slight bump on the floor) and then went off (or perhaps only went very dim - I panicked so I don't remember). I immediately unplugged my ballast fearing that a power-outage was imminent. I use my ballast for MH whenever my high-pressure sodium (HPS) bulb isn't in use (ie, during dark period of 12/12). I haven't had any problems after about 3 weeks of use, so I don't suspect the ballast. When I put the MH bulb in and turn on the ballast, the MH comes on, but it never gets entirely lit. It just stays dim, and my ballast makes a noise like it doesn't normally (a higher-pitched noise). Also the MH bulb appears to make a high-pitched "whine". I know my ballast does have a period of "warm up" where the light won't come on at all (and it makes a similar higher-pithced noise as well). My HPS bulb works fine. Is this a sign that my MH bulb is burnt-out? If it's burnt-out then why does it look like it "wants to come on"? Don't light-bulbs usually only burn out after constant toggling on and off? This bulb is relatively new and unused. How long do MH bulbs usually last? Could it be damaged? I always use a paper-towel to wrap the bulbs in when handling them, so I don't see how I could have gotten residue on the bulb unless it was on the paper-towel. The bumps just seem like a coincidence. My neighbors' make bigger vibrations than the ones I made. Besides, the light is suspended from the ceiling - a bump on the floor really shouldn't effect it much. I noticed that the "little bulb inside the bulb" seems to have a 'cracked' pattern at the one end, and some sort of non-bubble abrasion (not a burn mark) along the length. Or could it be a problem with the ballast that is specific to MH bulbs (like I mentioned, my HPS still works)? I'm not sure about the specifics of my ballast, all I know is that both bulbs have been working fine up until now. Could it be that my ballast shouldn't be used with MH bulbs, and thus destroyed my bulb before it's time?

On a somewhat related question, do these bulbs (MH and HPS) emit some sort of fumes? I noticed when putting my HPS bulb in, there was this smell somewhat like kerosene. It could've just been my new nutrients combining with the smell in the air.

I hope you are not connecting your MH bulb to an HPS ballast, as this is a no no.
MH bulbs need to be connected to an MH ballast, and HPS bulbs to an HPS ballast.
The exception is if you have a switchable ballast, which will power either bulb.

Well I assume it's a switchable ballast, but I'm not positive. Wouldn't one of the bulbs have blown weeks ago if the ballast isn't a switchable one?

A true switching ballast switches more than an ignitor. It switches taps, caps, and ignitor.

The funny markings you describe are probably the result of excess tungstun splatter.

You can count yourself lucky that your bulbs failure was not catastrophic. A ruined bulb is getting off easy imo....just ask our posterchild for idiocy

[thnx fmrgrl]

It is NEVER a good idea to put anything in a ballast but the
bulb that it was intended for.

Wow. Did the bulb explode or something? Did it knock all of his teeth out too?!

It would seem to me that if this was so dangerous, there would be at least some type of warning label or something. I got my ballast from a friend and he was doing the same thing. I should probably show him that pic - as he is a hell of a lot less afraid of electricity than I am.

Also,I'm under the impression that there are more than 1 type of ballast. Mine sits on the ground, plugged into a wall, with the hood plugged into it.


Thanks for the heads up.

Uhhh...you 'assume' you have a switchable ballast? If it has a magnetic coil then there should be a switch on the outside of the case tagged something like 'MH' and 'HPS'. It's my understanding the newer digital ballasts are plug and play for either MH or HPS. Then you can always 'switch' the ballast between 110 and 220VAC. I'm running mine off 220 and had to go inside the case to rewire it. If you don't know what equipment you're running...