How many plants can I vegetate under a 400w MH

Hey, I'm setting up a grow room today and since I don't have two lights I have to make the veg room the flower room and save up for another month until I can get a veg room...

Anyways I am not too sure on how much light a plant needs during vegetative stage, I've heard that it's not as much as flowering. Now if thats true then how many plants do you think I could fit under one 400 watt MH light?

Or is there a better way to build a veg cage?

You can veg as many or as few as you like. It all depends on how large you intend to flower them with respect to your size restraints. You could veg 100's under a single light or you could veg 1. All depends what your game plan is come flowering.

what size light are you going to flower with the same 400MH ? that is the key here. If I had to pick one light for the entire thing it would be HPS start to finish.

Under a 400 I would 6 to 8 and not let them get very big in veg. 400 watt light is only good for 24 inches of penetration. no sense in growing trees. And 8 is really pushing it.

Unless he fancies doing 12/12 from seed or clone, then 8 is anything but pushing it. Hence the importance of the flowering game plan. He has to know what size plants he wants to grow before he can decide how many.

Yeah I plan to do about 18''-24'' tall plants and then switch them to a Flower Room that has a lot more space and lighting. I just wanted to know because I like the idea of continuously running the setup for a 1 plant a week harvest.
With the Veg room I'd just have a bunch of plants that I can pick from and just was curious on the average amounts of vegetative plants under that light, I was thinking about getting a 2 tube 4' T-5 Fluorescent setup for clones and seedling and possible a separate room for some true keeper-quality mothers.

18 to 24 is too tall in veg for a 400. you will be wasting the veg time , the lower buds will get no light in flowering. they are going to double or triple in size in flowering I wouldn't let them get over 10 inches then flip them to flowering. just me.

wiseguy316 said:

18 to 24 is too tall in veg for a 400 without side lighting. you will be wasting the veg time , the lower buds will get no light.

Click to expand...

OK, thats what I was afraid of. Two questions now, so lets say I do 6 plants under a 400w MH- How much side lighiting would you recommend?
second question- if I were to use a 600w MH how much canopy penetration is that good for?

A 600 is good for 36 inches of use able light. As far as side lighting, anything you can come up with. CFLS, tubes more the better.

You really want an hps for flowering.

Alright for sure, so I'd be good with a 600w light with no side lighting then?

sorry for all the questions i just want to be sure before I go buying anything

Edit: Yeah I'm using an HPS for the flowering room and a mh for the veg room.

Again even with a 600 it depends how tall you let them get in veg as to if you need any side lighting. Look into a digital dimmable ballast. That way you can possibly use it for veg and flowering and just have some different options. It will run both bulbs MH & HPS.

Don't worry about the questions we are here to help.

Alright thank you

Just for a heads up my friend has tried the system I'm using out and has had decent results so I'm not worried about the Flower Chamber, I don't want to seem like spam but he copied this guy and I'm copying both of them haha https://www.rollitup.org/newbie-central/360125-new-growers-needed-grow-lab.html


Anyways, I already have a Digital dimmable ballast and I was going to use that until I had enough for a Veg Cage. The way I'm going to grow like a gnarly way of scrog where you bend the plant around the buckets diameter(I learned this from the thread above) after they've reaced a height of about 22'' topped.

I want to have a half and half garden(half bent around bucket and half grown normally vertically) so that if I screw it up my first time I have some normal plants to still harvest

Ok so I got 8plants is max to veg 12/12. How about if your doing scrog at 12inches? Think I could fit 10 good sized plants ready to be moved into an other 400watt hps veg room? Maybe room to grow 12/12 seed(is it a good idea to scrog 12/12 seed thats an other q)?