...Hmmmm. Well, doing a sea of green in a small space like that, I'd suggest lollipop'n your plants, and prunin' the large fan leaves.
Here is a good read for you :
How much will I yield?
"I have XXX watts...how much will I yield?" or "How can I get
bigger yields?"
A common inquiry. From ambitious new gardeners and for good
reason too. But, this is really a loaded question that doesn't
have a definite answer. It seems one of the first assumptions by
new gardeners is that loads of light automatically equals loads
of buds. Unfortunately, it's just not that simple. Yield is
equally contingent on a number of factors; light, temperature,
humidity, water, nutrients, CO2/ventilation, genetics, etc. Think
of it as an engine, with each factor of cultivation representing
a single piston, sure the engine will run if some of the
cylinders are misfiring or not firing at all, but to yield the
most power from that engine, all cylinders must be firing in sync
and at maximum capacity.
Temperature. Most cannabis plants will slow or cease growth when
temp's get above 85F, or below 65f. Optimal lights-on temp for
most strains is about 72-78F, with 5-10 degrees cooler during the
dark period being a good rule of thumb. (Unless co2 is used)
Humidity. Cannabis does best around 45%-55% RH (relative
humidity).
During veg and late flower, however letting it drop lower during
the final two weeks of flower is advised, as it will help prevent
mould problems.
Water/moisture. Cannabis generally doesn't like "wet feet", or a
soggy environment, so it's very important to have a fast draining
soil/soil-less mix (or well aerated solution in a hydro garden).
Wet or damp conditions can also lead to mould problems during
flowering.
Nutrients. Cannabis will require a variety of nutrients at
varying NPK ratios during its existence. NPK stand for; nitrogen
(N), phosphorus (P), and potassium (K)-the three major nutrients
used by plants. Simply put, your plants will need a fertilizer
with more N than P and K during vegetative growth and fertilizer
with more P than N and K during flowering. Using any well-known
quality fertilizer applied per instruction @ ½ strength is a good
place to start. Organic, chemical, or somewhere in-between is
another choice to be made and is a totally personal one. There is
a plethora of fertilizers on the market, but the best fertilizer
is the one that's used properly.
CO2/ventilation. Plants require CO2. There is sufficient CO2 in
our atmosphere to support massive bud growth, but when growing
inside you must either have adequate ventilation (the volume of
the room exhausted at least once/5 minutes) to ensure that there
is a constant supply of fresh, CO2 enriched air or one must have
supplemental CO2, which requires higher temp's and more nutrients
to be utilized effectively.
Light. Typically, the more the merrier, but more light will
create stronger water, nutrient, and CO2 demands on the plants.
You must also have the proper spectrum of lighting as well as a
means of efficiently reflecting as much of the light as possible
into the garden's canopy. The norm is to use more bluish light
(Metal Halide, cool-white fluorescents) for vegetative growth and
more reddish (High Pressure sodium, warm fluoro's) light for
flowering. Though it's possible to grow great buds under
fluorescent lighting and a few will even argue their superiority
to HID's, most indoor growers use High Intensity Discharge lights
such as MH and HPS, and many use fluoro's for vegetative growth
and HPS for flowering. It's very important to have the light as
physically close to the canopy as possible without burning the
foliage and still allowing for even coverage.Many new growers
believe that "Droppin the light" closer to the plant will be
beneficial. Besides heat stress, the bulb puts out radiant energy
that causes leaf burn (Note it is possible to complete a grow
using just HPS or MH)
Genetics. Its an easily overlooked factor. Some strains simply
have the potential to yield more than others. Having a
heavy-yielding strain doesn't automatically equal big yields,
either. It only means that the potential for heavy yields is
there. The grower must provide the optimum environment for that
particular strain in order for it to be able to reach it's yield
potential, and each strain has slightly unique requirements.
Also, within a strain there are usually several phenotypes, each
of which will exhibit unique characteristics which is to say that
some pheno's of a particular strain will weigh more than others.
Plant/root/container size. Obviously, the longer a plant is
veg'd, the bigger it will get and the more it will yield. Almost
always overlooked because they're unseen are the roots. Root mass
is directly related to bud production. Simply put, the more roots
you have the more bud you will (potentially) have. Be sure to
always allow plenty of space for the roots to grow and spread
out, even more-so in soil A general rule of thumb is 1 gallon of
soil for every foot of plant height. This is also the reason I posted
the thread about air-layering, titled bigger yeilds for your plants.
System.
Scrog/Sog/Vertical gardens
These systems have a higher g/w/time yield than comparable large
plant system over the same time period.
Grower's skill. Growers can add yield by: using additives (like
B1, kelp, enzymes), foliar feeding, and topping/FIM/
In addition. Tricks like keeping nutrients and the air temps warm
during night cycle can help final yield. Although it's a topic of
hot debate, it's generally thought that any system that supplies
the roots with maximum oxygen (aeroponics) would outperform a
system that restricts 02 input such as (soil).
So, as you can see there's much more to yield than throwing some
plants under tons of light with tons of nutes. Before one becomes
too concerned with yield, one must first learn how to grow plants
well, learn how to "listen" to the plants and give them just what
they need. It's best to start with simpler methods, in fact, I
think the simpler method is always the better one. Learn how to
grow strong, healthy, fast-growing plants and the yields will
come.