400w MH fixture help

Hello guys, i want to ask you a question about this matter.
I found in my garrage a MH lamp.
Its a 400w MH lamp fixture with a Sylvania 400w bulb
Today i want to test it to see if it still works.
My big question is - can i use a 250w HPS bulb with this fixture ? I saw that has an ingnitor but im not sure if the HPS bulb work with this MH ballast.
I attached some photos with all the pieces in the lamp, hope someone good at this help me out here

Any help would be kindly apreciated.

You can use a bulb with a higher wattage in a lower wattage ballast. If you try to use a 250W bulb in a 400W ballast it will not work.

I

HydroRed said:

You can use a bulb with a higher wattage in a lower wattage ballast. If you try to use a 250W bulb in a 400W ballast it will not work.

Click to expand...

No, i made a mistake in the first post.
It is 400w ballast with 400w MH bulb.
The question is can i use a HPS bulb with that fixture? Would that ignitor in the pics work ? I dont want to mess up something.

No its a 250w light it says it right in the first pic and no that mh ballast won't fire a hps bulb and your risking a fire if you try

I was under the impression that HPS ballasts have ignitors and MH dont? You sure thats not a HPS ballast? and it is 250W says it on the ballast.

EG beat me to it. Im a slow typer in the AM lol

HydroRed said:

I was under the impression that HPS ballasts have ignitors and MH dont? You sure thats not a HPS ballast? and it is 250W says it on the ballast.

Click to expand...

Pulse start mh lamps have an ignitor

I have 2 lamps. Probably i make pics to the 250w. I put some new pics with the 400w lamp

If it has an ignitor than it is for an HPS. A MH bulb will work on a HPS ballast, but an HPS bulb wont work on a MH ballast since the HPS needs an ignitor to fire and the MH doesnt. Digital ballasts usually run both and switches internally. Some magnetic ballasts have a switch to run either one.

evergreengardener said:

Pulse start mh lamps have an ignitor

Click to expand...

So a pulse start MH will still fire on a HPS ballast then right? Or are the ignitors different from HPS to pulse start MH?

HydroRed said:

So a pulse start MH will still fire on a HPS ballast then right? Or are the ignitors different from HPS to pulse start MH?

Click to expand...

I'm unsure that's something to look into.. but I wouldn't risk it a good switchable ballast cost less than a zip nowadays. Shit you can get a cheap setup on amazon for like $180 that includes hood ballast bulbs yoyos and a timer. So I wouldn't even bother trying to fire a hps on a mh ballast

evergreengardener said:

I'm unsure that's something to look into.. but I wouldn't risk it a good switchable ballast cost less than a zip nowadays. Shit you can get a cheap setup on amazon for like $180 that includes hood ballast bulbs yoyos and a timer. So I wouldn't even bother trying to fire a hps on a mh ballast

Click to expand...

https://www.amazon.com/VIVOSUN-Hydroponic-Digital-Dimmable-Ballast/dp/B00P8P50G6/ref=sr_1_4?ie=UTF8&qid=1475327773&sr=8-4&keywords=400+watt+hps&th=1
$145.99 with free shipping

Ok guys, this is the lamp that im talking about- the 400w MH
So you say that i cannot trplace the MH bulb with an HPS ? Im a little short in money and i eas thinking to veg with this 400w MH and for flowering to change to HPS

strobericaf said:

Ok guys, this is the lamp that im talking about- the 400w MH
So you say that i cannot trplace the MH bulb with an HPS ? Im a little short in money and i eas thinking to veg with this 400w MH and for flowering to change to HPS

Click to expand...

If its a matter of being short on cash, just grow under the bulb you have from start to finish, even if it is under a MH. 4000K isnt a bad spectrum to veg and flower under.

HydroRed said:

If its a matter of being short on cash, just grow under the bulb you have from start to finish, even if it is under a MH. 4000K isnt a bad spectrum to veg and flower under.

Click to expand...

thats quite true, problem solv-ed

Thank you guys.
I will try this grow with what i have at the moment.
I will try to keep u posted.

Thanks again for all the infos.
Cheers.

What size room will you be using it in? I think that light will do well in a 3'x3' if not too overcrowded.

Im using a 3.2x3.2x6.5 tent.
I hope for 6 plants .

U think that would be ok ?

6 *small* plants. You should anticipate them getting about 3x their size in the first 2-3 wks of transition from veg to flower. You also want to give em a little "shoulder room" as well so you can get some light penetration to the lower canopy and not be so inclined to overcrowd and get powdery mildew etc.
Post back in here so we can see what you end up doing.