Help with metal halide light question

So my set up is
2 plants Northern Lights
Doing bubbleponics grow
water at about 70 deg
Nutrients at full
plentiful air supply from stones
roots are very healthy looking with large mass

My friend gave a 400w metal halide Set up. They have been growing for a month now but with slow growth...dark green leaves, looks like its over watered, and the leaves are not "reaching" towards the light which is 1.25ft above plants with a light cooler. I looked at the light today and noticed it is a conventional light. My question is is that by not having a grow metal halide bulb the plants are not receiving enough spectrum of light?

Not positive but I think the grow metal halides have increased red/orange specturm for the flowering stage. A conventional bulb will put out plenty of light for 2 plants unless you've got some 7ft. monsters. You're light might be too close. Even without heat, plants can get stressed from having too much light. I was running a 400w HPS for awhile that didn't really get hot about 1ft above my plants and yesterday I moved them to a new spot where the light is at least twice that distance from the tops and I can already tell they're looking much better.

Standard metal halide bulbs will work fine as long as it's not old and worn out. Light output drops as they age, drops a lot. But your problem is that you have it so far away. That distance would be good for 600-1000w setups. Get a fan blowing on the tops of the plants and the light bulb and start dropping it down 12" from the tops or so or closer. You could probably easily get it to 8" without burning. A small difference in distance drops off the useable light the plant gets by huge amounts. Every inch counts.

If you don't know the age of that bulb get a new one and keep that one as a spare.

Alright thanks. well the light is only 2 months old and i have a fan blowing over everything. it might be too close because the one plant is only about 12" tall but is also 12" wide with many leafs and off shoots

It's only too close when the plant top leaves burn or sometimes growth slows to a crawl but 12" really doesn't sound too close for that bulb as long as your temperature is good in your grow space AND provided you have a fan on the bulb and the tops of the plants. If you move it too far away the plant with get taller faster but that's not a good thing it is called stretching and we try to avoid that usually.

If the plant looks healthy and has lots of side shoots and is as wide as it is tall that's a good thing.

Sounds to me like you're either just impatient or maybe something else is less than optimal. Plants take time to grow and they never do seem to grow quite fast enough when you feel in a rush and want to see things move along faster. However if a week goes by and you measure it's height each week and you don't gain an inch then something is wrong.

ok thank you. ill see what happens in a couple days