newb cfl closet grow

high times

Active Member
So I just go an OG Kush clone from the club about a week ago. Currently I have 4 23 watt cfls 2 6500k and 2 2700k I will be transplanting it into a 10" pot this weekend and will be using soil....duh....nthn special no fans or anything I live in a 1 bed apartment in a chill neighborhood so I can open the closet door if I want.
So my questions are Do I need more lights? Should I be using only 2700k bulbs? My plan is to veg for 4 more weeks and then flower is this enough time to completely lst in a 10" pot? Would this be enough time to do some combination of scrog and lst? I've covered the walls with tin foil the lights are about an inch away from the top of the plant.....
I'm a college student with my club card so please don't tell me to go get hps or mh lights because I cant afford them
Currently the clone is about 3 1/2" tall it has one mature set of leaves with a new set coming out on top (5th node, all other leaves were cut off but there is new growth at each joint, space between main stem and node)and a small set that died before I got it....any advice is greatly appreciated thanks in advance I will post pictures after I repot
 
from what ive heard tin foil is not good, it reflects alot of heat, and can burn your plant, i was told go with mylar,
just throwin an opinion out,.
and just measure the room, marijuanna is said to need 3000 lumens per square foot, you can run as much light from the cfl as you need, as long as you keep the temp. under control
 

Gastanker

Well-Known Member
Four weeks should be time enough for a small LST/scrog. I think mixed spectrum works better than just one but you def want more 2700k in flowering compared to the 6500k - more lights the better. Cant wait for pics!
 

TeaTreeOil

Well-Known Member
Reflective Mylar derives reflectivity from aluminum, and a very small amount of it deposited via a process termed metalization onto plastic(PET, or polyester).

Tin foil... a very unpopular foil used in the early 1900's, is hard to come by these days. Aluminum foil is better at protecting foods from harmful rays and doesn't give foods a 'tinny' taste, and largely replaced tin foils several decades ago.

The difference between reflective Mylar and aluminum foil is mainly due to thickness(most important), and absolute surface smoothness(secondary). That is, if it's not thick enough, light will go right through it more readily. The major difference between thick reflective Mylar and Al foil is the smoother surface of the Mylar. This allows it to better reflect light directly, instead of diffusing the light. Al foil is about 50% diffuse, while aluminized Mylar half that, 25%. How directly light is reflected is termed as the specular coefficient(sometimes termed by 'mirror', or 'solid reflection'). Most Al foil is around 70-90% specular, depending on the side of the foil. Mylar is over 90% specular(like a mirror, which is nearly 100% specular and has very little diffuse, under 20% typically, and the better the mirror the lower this value. Less glare, less diffusion, more of a solid image(reflection), also mirrors of this caliber are typically made from silver. This is measured as image clarity.

Specular and diffuse do not change the total reflectance, which is a total measure off the surface irrespective of diffuse or specular coefficients; however, they will change the lux measurements greatly. Diffuse surfaces lower average lux more rapidly at as distance increases, as the light is spread out over a greater area while the energy is equal. Specular surfaces will provide a higher lux where there is directly reflected light for the measure, and far lower where light is not directly reflected, as the light is not spread as greatly. This is sometimes termed as luminous throw, how far the light travels in a direction with intensity.

For example, take some BBs versus a pin ball(both equal in mass), throw either at a target(with a single throw), like a glass bottle. Which would do you think is going to be more effective at knocking over the bottle or even breaking it? Certainly the pinball, if it strikes. Otherwise you're pretty much guaranteed one of the BBs will hit the mark... but that's not very effective, it won't move and won't break.

You may ask wtf does that have to do with light? Well, light has mass, and light creates pressure, also momentum, just like those metallic balls. Kind of like comparing a bulb with a reflector to a bulb without one. The bulb with the reflector increases lux and throw in a certain direction. Without the reflector, it's the same amount of light, but far less lux, as the light is going in every direction, just like a diffuse reflector.

Flat white paint is typically over 85% diffuse, and has a neglible specular coefficient. It's very poor at throwing intense(direct) light, but it's great for spreading light evenly.

--

CFLs are highly efficient for veg growth. Two of those 6500k can handle the plant to about 1'. 2700k is for flowering, don't bother with them in veg, the spectrum provided isn't that useful for vegetative growth.

Once it gets to a foot, use all 4 bulbs. Two feet, consider doubling it, and again every time the plant size doubles.

You can finish in 10" pots. As long as you're not growing trees.
 

arcticvapors

Well-Known Member
Reflective Mylar derives reflectivity from aluminum, and a very small amount of it deposited via a process termed metalization onto plastic(PET, or polyester).

Tin foil... a very unpopular foil used in the early 1900's, is hard to come by these days. Aluminum foil is better at protecting foods from harmful rays and doesn't give foods a 'tinny' taste, and largely replaced tin foils several decades ago.

The difference between reflective Mylar and aluminum foil is mainly due to thickness(most important), and absolute surface smoothness(secondary). That is, if it's not thick enough, light will go right through it more readily. The major difference between thick reflective Mylar and Al foil is the smoother surface of the Mylar. This allows it to better reflect light directly, instead of diffusing the light. Al foil is about 50% diffuse, while aluminized Mylar half that, 25%. How directly light is reflected is termed as the specular coefficient(sometimes termed by 'mirror', or 'solid reflection'). Most Al foil is around 70-90% specular, depending on the side of the foil. Mylar is over 90% specular(like a mirror, which is nearly 100% specular and has very little diffuse, under 20% typically, and the better the mirror the lower this value. Less glare, less diffusion, more of a solid image(reflection), also mirrors of this caliber are typically made from silver. This is measured as image clarity.

Specular and diffuse do not change the total reflectance, which is a total measure off the surface irrespective of diffuse or specular coefficients; however, they will change the lux measurements greatly. Diffuse surfaces lower average lux more rapidly at as distance increases, as the light is spread out over a greater area while the energy is equal. Specular surfaces will provide a higher lux where there is directly reflected light for the measure, and far lower where light is not directly reflected, as the light is not spread as greatly. This is sometimes termed as luminous throw, how far the light travels in a direction with intensity.

For example, take some BBs versus a pin ball(both equal in mass), throw either at a target(with a single throw), like a glass bottle. Which would do you think is going to be more effective at knocking over the bottle or even breaking it? Certainly the pinball, if it strikes. Otherwise you're pretty much guaranteed one of the BBs will hit the mark... but that's not very effective, it won't move and won't break.

You may ask wtf does that have to do with light? Well, light has mass, and light creates pressure, also momentum, just like those metallic balls. Kind of like comparing a bulb with a reflector to a bulb without one. The bulb with the reflector increases lux and throw in a certain direction. Without the reflector, it's the same amount of light, but far less lux, as the light is going in every direction, just like a diffuse reflector.

Flat white paint is typically over 85% diffuse, and has a neglible specular coefficient. It's very poor at throwing intense(direct) light, but it's great for spreading light evenly.

--

CFLs are highly efficient for veg growth. Two of those 6500k can handle the plant to about 1'. 2700k is for flowering, don't bother with them in veg, the spectrum provided isn't that useful for vegetative growth.

Once it gets to a foot, use all 4 bulbs. Two feet, consider doubling it, and again every time the plant size doubles.

You can finish in 10" pots. As long as you're not growing trees.
...my brain hurts now...:bigjoint:
 

TeaTreeOil

Well-Known Member
My brain hurts every time I see tin foil mentioned. Because tin doesn't create hot spots, it's a mediocre IR reflector. Does alright with UV, but aluminum is better in pretty much every regard.
 

cantbereal

Active Member
so is a mirror better than Mylar ? I have a cheap light meter and the chip bag reads almost the same as the light from 4 inchs. Do you think the 1 foot square mirrors from HD would be better of are they too cheap of a mirror.
 

TeaTreeOil

Well-Known Member
It depends on the mirror, but technically a silver mirror will far surpass Mylar in image clarity and specular intensity. Higher quality aluminum mirrors could also be superior, all Mylar is not created equal, neither are mirrors. A silver mirror is a nearly perfect reflector(over 99%), though.

Silver isn't that great at reflecting UV by itself, which is why aluminum is the best choice, as it's naturally great at reflecting UV to IR. A thin aluminum oxide coating forms and is an excellent barrier against further oxidation and degradation. Aluminum oxide is 3x stronger than steel and is semi-transparent.
 
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