plant/light ratio?

[KP419]

How many plants could a 400watt hydro farm ballast sufficiently grow?

 

[7greeneyes]

what's the dimensions of your grow?

 

[4u2sm0ke]

2x2

 

[astrobud]

:yeahthat: about 2 plants

 

[bubba902]

Hey KP419 nice digits ...
I ran my hydrofarm 400w in a 4x3x5 ontop of 5 plants, I only ended up being able to fit 4 comfortably if your in a 2x2, You want to give each girl about 1 sq ft or more (that's what I have always heard atleast)

 

[7greeneyes]

if i'm using it to bloom: 4 only

if I'm vegging: dbl that amount depending on pot size, also my prop chamber and seedlings to the side.

 

[KP419]

My room is 8x5.

 

[Hushpuppy]

That room is waaay too big for a 400w light. I like to get about 7500lumens per sqft in my grows for flowering to get best results. You have a 40sqft area, which would need 300,000 lumens to sufficiently flower. That would need 5 600watters or 3 1000watters. What you can do is close in an area that is 2'x4' or 3'x3' with reflective material and either grow 2 medium plants or 4 small plants.

Me personally; I would divide the space in half and get 2 600w HPS and put in one space for flowering and use the 400w in the other space with a high blue output metal halide bulb (if your 400w ballast is digital or switchable between MH and HPS) for vegging clones.

 

[7greeneyes]

hushpuppy has some sound advice :aok:

 

[KP419]

Thanks for the advice hushpuppy! I used a sheet of plywood and covered one side with mylar and cut the size of my room in half and the light my plants are getting now is just insane. I believe that was my main reason for plants taking forever to start flowering. This was the biggest room I've ever used and have never had problems before but past rooms were never as big. so hopefully i can make up for lost time now. thx again

 

[The Hemp Goddess]

Thanks for the advice hushpuppy! I used a sheet of plywood and covered one side with mylar and cut the size of my room in half and the light my plants are getting now is just insane. I believe that was my main reason for plants taking forever to start flowering. This was the biggest room I've ever used and have never had problems before but past rooms were never as big. so hopefully i can make up for lost time now. thx again

While it make appear that your plants are getting an insane amount of light, they are not. You are still really underlit. A 400W HPS is good for about 9-10 sq ft. A space that is 20 sq feet needs another 400W or a 600W (even a 600W is pushing it) or a 1000W. I run either 2 600w or 1 1000W in a space that is 20 sq ft. A space that is 20 sq ft with a 400W is only getting 2000-2500 lumens per sq ft--not nearly enough. Inadequate light will result in slower flowering and light airy buds.

 

[Hushpuppy]

Yeah, THG is completely right about that. That is why I said I would divide it in half and put 2 600wHPS in one room and use the 400 for vegging in the other room. To just use the 400 right now means to close that space in more than just half way.

 

[bubba902]

couldn't he get away with buying (1) 1k watt ballast, and a splitter for 2 600's? cheaper/ little bit better light cover also... jmo..

I think I may just become a seasonable OD grower lol. Seem's cheaper on the electric bill

 

[bubba902]

With that hydrofarm hood/ballast, do you have another 400w to supplement with? even a batwing'd one could help open up a bit more room for ya.