Need Help 400 watt mh light adjustment

Yeah mh can be awkward to get right for seedlings,

none the less, hold your hand above the tops of the plants,,if you can feel the heat so can the seedlings, so raise /lower till it dont feel hot on the back of your hand.
Are you also venting the tent and the light? As that could help lower temp. Im just trying to convert that to degree c, so like 27-28, yeah thats not too bad, but could be lower. The other thing is when you transplant them you can bury the stem down abit so its not as long and lakey, also roots will grow from the stem.
Im not running a mh in veg anymore, but still using a 400w hps in a adjustwing and have that alil under 10inchs from my tops, but they aint seedlings.
Is that cir fan not keeping them nice and cool under the light? That will slow down the stretch having the fan trained on them but if its blowing 24/7 it could dry them out and or stress them, the high heat will also contribute to the stretch. And with the high temp you keep the light away from them and they stretch more etc... Yeah dilemma ay.

edit. Forgot to ask, what Humdity is it in there?

Take it easy.

Ha, also, i run my 400w at night, and my veg tent day, maybe if you dont already that could be an options.. Take it easy.

humidity is around 40%-45%. It actually feels a lot better in the tent than it says for temp. They already have there first two single leaves and they are working on there 2nd pair of single leaves. The stretch seems like it stopped for now but the hand under the light test seems like they could be closer. Yet when I read what people write they seem to be leaning torward not puting it closer than 12 in. until after the first week or two. Not sure what to do.

Ha, yeah, i certainly wouldnt stress over it, they are clearly growing, and yeah, until those first true leaves come in they can only take so much light.
Guess if you are really unsure you could prop one up on a small box or up turned pot and see how it compares and see if it stretchs more etc.
if you can try up your humidty,,mind that glass though,
but yeah, i think now would be when you should think of re potting and slowly closing the gap, im sure with air cooled you can get mega close, and thats the point, so maybe just slowly decrease the distance, from now and repot the stems down when you do repot.

Best o luck.

I personally pour more soil/medium in around the new plants that stretch like that and press it down to give them more support, up to the leaves at least. and here's the chart that tells you how far it needs to be View attachment 2857374

In response to your chart. My 400 watt MH is more lumens than what is listed there because I have a digilux bulb. Also how many foot candles does a seedling need, vegging need, and budding need? Never heard much about that measurement. Thanks

with my 1000w mh I use, i dim it down to 50% with 6-8 seedlings, all it has is a cool tube and i keep it 8-14 inches away. foot candles aren't important, that's just how many candle power shit at 1 foot, their measurement for lighting power. Just put your hand under it to see if it's too close at 6-12 inches, if it feels good to you it'll feel good to them ^_-

So I could dim my lumatek ballast down to 360 which is as low as it goes? maybe that will help. My ballast can go 360-400-600-super lumens.

seedlings don't need as much light as when they get heavy in the vegging and flowering. 50-75w per seedling is my measurement until they get about their 2nd node, then it's all 100w+ from their per plant for me ^_-

So I dimmed my ballast to 360 and left the light at 12 in. from the tops for now. We will see how it goes I guess.