added cost Vs reward

[epicstuff]

Will I get a significantly worthwhile increase on yeild on 6 plants by having 2 x 400W SOH instead of 1 in my setup. was going for just 1 but after some reading it seems rather underpowered.
Bearing in mind I cant find CO2 cylinders locally which I really want.

Will the extra light without added CO2 justify the cost of extra light units. room is 7.5M by 4M with extraction fan but no intake. ( plenty of gaps for the air to be pulled in from).

My goal I'm aiming for is 1 kg from those 6, I've chosen high yielding Plants, 5 xbig bomb and 1 or possible 2 others, not sure which one to leave in the grow room, choice of: skunk#1 / royal queen fruit spirit or auto flower NL .( I know bad move getting an auto flower as I'll have to flower the rest any way, I just needed to bump up my order to justify the postage cost and it was the only NL they had, not really worth gettin a seperate system just for 2 autos is it?)
The rest I'll stick outside with a couple of Sleestacks, to make more space and to experiment on the yeild differences. Any recomendations which of those mentioned will be best in side and which to take out side. I geuss i need to try keep similar size plants inside. but also which do best in as opposed to out.. Ummmmm.... so many discissions !!!

 

[Growdude]

7.5 x 4 meters, you are so under lit.
you need over 31, 400 watt lights.

 

[pcduck]

7.5 meters x 4 meters is 30 sq meters which is almost 98.5 sq feet.

That is a major size room for just 6 plants.

If you mean feet instead of meters then you have 30 sq feet.

30 sqft x 5000 lumens = 150,000 lumens needed.

You are still under lit with 2 400 watters would need 3 400 wattters or 2 600 watters. Co2 is not needed as you are under lit and not worth the cost.

I would make a passive intake, get more light, then maybe Co2, if you think you need it. When using Co2 high lumens and temps will help with the absorption of the Co2. I do not use it in a 4' x 4' tent with 2 600's in it and the buds will put your eye out if not careful.

 

[epicstuff]

No ,, I mention the size of the room just to put the air availability and circulation in perspecive I'll be using about 2M x 2 Meter area for plants. I got an old 4 poster bed I was going to use to tent up for grow area.

So in feet that 40sft roughly ,, yes.... so I will need at least 2 lights. really a 3rd If I want to get the cuttings gowing aswel. **** the cost keeps going up. hope the end justifies the means...... Any comments on
1 kg being achieveable with 6 plants with 800w big Bomb seeds? or am I dreaming...

 

[pcduck]

No ,, I mention the size of the room just to put the air availability and circulation in perspecive

This will not matter once you close off the grow room. And you really need to otherwise you are wasting a boatload of lumens.

I'll be using about 2M x 2 Meter area for plants. I got an old 4 poster bed I was going to use to tent up for grow area.

These are the numbers that matter, not the outside area of your grow room.

So your grow space is 2 meters x 2 meters = 4 sq. meters x 5000lumens/sqft = 211,250 lumens approximately needed. 2 400's will be severely under lit.

 

[The Silver Bullet Special]

Make sure your flower room is light tight! You dont need an intake fan, most people just run a passive intake which is just a hole in the side (sometimes with a screen to filter the air) to allow air to be drawn in. You want a fan to exchange the whole volume of air in your grow room every 5 minutes or less.

Thats cubic air volume not square meter/feet; so your calculations would be LxWxH and thats your cubic air volume. You might want to get a fan that pulls more air than you really need and put it on a speed controller so it doesnt run the fan to the max and makes it last longer.

 

[Hushpuppy]

If I understand you correctly, you are only vegging the plants indoors? and intend to move them outside to flower? If that is true then you won't need quite as much light in your space. For vegging plants either T5 florescent lights or metal halide work, and you want to have over 3000 (4000 is better) lumens per square foot of lit area. If you are using High pressure sodium lights in your grow area that is ok for vegging but the blue-white light is better for veg growth. And yes, having more, proper lighting that is more expense is totally worth the cost for the reward as MJ is a very high energy plant. getting 1kilo is certainly doable but more light is needed to achiev that.

 

[epicstuff]

cool good feed back ,, I am planning on working upto a more professional set up as I build up my stock of decent cuttings hoping 4 sq M to have 4x 400 HPS. money issues force me to take step at a time... Hence just wanted to spend the min. to ensure a first time reasoanble crop to ease the way.. I remember getting 1kg regulaly many years ago using a 400w but I remember also now , that I did have a bank of tubes I used with that set up..
I know now I made many mistakes in those days , I never lollipoped them or topped/ Fim'ed them. so I'm hoping with those techniques I will improve the harvest considerably. I also plan to give them a little more space to fill out that way I can take them out side for company on hot, clear days; for a few hours now and then.

 

[Growdude]

I remember getting 1kg regulaly many years ago using a 400w but I remember also now , that I did have a bank of tubes I used with that set up..
I know now I made many mistakes in those days , I never lollipoped them or topped/ Fim'ed them.

Then I would stick to whtever you were doing.

 

[pcduck]

:yeahthat:

If you are getting 35 ounces from a 400 watter, stick to what you are doing

 

[bubba902]

Holy mamba jamba grow man! 35 zips from a 400w?

Wish my 400w hps setup could of done that!
what were you using?! Miracle grow?!

Okay jokes... i stop now

 

[bwanabud]

Any comments on
1 kg being achieveable with 6 plants with 800w big Bomb seeds? or am I dreaming...

You ARE dreaming, won't happen now, or "many years ago"

 

[epicstuff]

does seem hard to believe , I question my own memory.. but was sure I getting around that, I had 8 plants in hydro system maybe another 4 or 5 in pots just around for a ittle extra . 400hps and I'm geuessing about 12 or so tubes in and around the plants. Mother was using an old sun bed. she mutated after about 4 or 5 grows. into thick cheeseplant leaves. geus she didnt like the UV.

 

[Hushpuppy]

Maybe that was wet weight