many questions

How long can i keep a 75 watt bulb on my plant? Its been 3 days now and i have 2 plants started how long can i keep this bulb on my plants. Also what is the light cycle i should be using? Right now i am on a 20/4 cycle.

Can anyone help me please ????

 

75 watt bulb?
you will get much better results with a fluorescent light!
starting seeds?24 hour light!
transplant and keep under fluorescent till about 6 to 10 inchs tall!18 hrs light 6 hrs dark
after that,they need more light!
put outside,build a greenhouse.put transplanted plants in,no direct sunlight for one week!after that grow in greenhouse till one foot tall,direct sunlight.
then put in ground and watch them grow!
inside?you need metal hylide light to veg,
high pressure sodium to flower.

 

personnaly i use 2 100watt normal light bulbs and my plants are great its only 3x3 feet in my grow area but theire exelent and growing very very fast aswell.

 

normal light bulbs are a waste of energy and time.
much cheaper and better are fluorescent lights.

 

ive tried fluorescent lights but theire not bright enough so ive got 2 50watt halogen desk lamp that make the area im growing in (surounded by reflective sheets) so bright, as as said my plants are doing awesome

 

100 watts of halogen and they are doing great?????? How wrong you are my friend. They are probably growing really fast, with several inches in between nodes( sets of leaves growing of the stem). That is because you have virtually no usable light for plants. In low light conditions, doobage plants grow very tall very fast, because they are starved for light, and are reaching for every possible lumen available. stick with hid lighting, MH will do for both veg and flower, but HPS is preferred for the flower. Dig deep in your wallet and spend the money for a decent light. I guarantee you will get your moneys worth in buds in a matter of months. Growing indoors is a science, you must treat it as so. Just throwing whatever lights you found in the garage on a few plants in a closet wiull not be worth your time.

 

Compact florescents work great, and they fit in standard light sockets.
a (good quality) 23W CFL will produce almost 1500 lumens. With 2 CFL's per/ft2 your plants will love you. (Be careful that the manufacturer actually states the lumen output, and not the 'equivalent output')

1 23W CFL will produce almost as much lumens as a 40W tube, and the light is concentrated to 6 inches, instead of 4 feet.
In terms of effective lighting, I tend to think that CFL's are better than HID's even, although not as energy efficient, and the cost of replacement is MUCH more.

Although the CFL's are more expensive to maintain, they are much more configurable than any of the other lighting options. This allows you to make more efficient use of your light output and likely require less actual lumens per/ft2 since you won't be wasting as much light.

You can buy CFL's in packs of 3 for about $12 to $15 (Canadian)

I have not seen them myself, but apparently you can also get high wattage CFL's, such as 120's, and they are even more efficient, but they use a larger socket than a standard bulb.

 

No compact flouresent even comes close to hid lighting, as of yet. to light a 3'*3' area, you would need at least 6 or 7 of the 75watt fixtures, to get good tight dense bud development. The cost of buying all those ( they are about 40 bucks american at home depot/menards) would be more expensive than a 1000 watt H.P.S. Go to http://www.insidesun.com/ They have 1000 watt H.P.S. for 200 bucks. And by the way, compact flouro's cannot be placed 1-2 inches from the tops, the plants will DEFINITLY burn. The closest you can keep them is about 5-6 inches. So if you have 6-7 of those times 2000 lumens, you have 12000 lumens. Now compare that to the 140,000 you get from a 1000 watt H.P.S., and there is no comparison

 

I buy 23W cfls in packs of 3 for $15 Canadian.
They produce 1600 lumens each, and they are good for 8 to 9 months of constant use.
The efficiency factor is 70 lumens/watt.

An 400W HPS will output 45k lumens. Which is 112 lumens/watt.

However. Illuminance is not the same thing as lumens.
The lumen rating is the amount of light that is radiated at a distance of 1 foot from the source in all directions.
A candela is the amount of light radiated from a source, that reaches a target of 1 square metre at a distance of 1 metre away.
To convert that to foot-distance, divide lumens by a power of 3.81 for every foot away and for every sqft of area to be illumated.
Don't forget that the distance from the lamp to the plant is line of sight, not vertical.
And also don't forget to factor in the size of your plants and how much lumens you want to reach the bottom of your plant.

Now to add to the equation, in our circumtance, we are redirecting half or more of the light with reflectors, so you can basically double the rated lumen output.

As an example, if you have a vertically mounted 400W HPS with a round reflector. If
the bulb is rated at 45k, you can begin the illumance factor with 90k and a distance of 1 foot away already.
So now lets say you have your light hanging 2 ft above your plants in a 3x3' area and your plants are 3 ft tall at maturity, which is pretty small for grown under HID. Only the top half of the plants will be worthy, so the distance to the middle of the plant in the center square from the bulb is 3.5ft.
We can subtract 1ft because lumens are based on a 1ft radius, so we have 2.5 feet.
Now divide your lumen output by 3.81 to the power of 2.5. In other words.. 90k / 3.81 / 3.81 / 1.905 = 3254 lumens for the middle of the middle plant.

Now each plant on the skirt is not directly under the light, but 1 foot horizontallly removed. If you measured from the bulb +1 ft (for lumen measure) to the middle of an outer plant the distance would be (find the length of the 3rd side of a triangle) 2.7 ft.
The lumens reaching the middle of the outer plants is 90k / 3.81 / 3.81 / (3.81 * 0.7) = 2322 lumens.
Big difference for simply being 1 ft away horizontally isn't it?

Now with 2 23W CFL's /sqft over a 3x3 area is that is a total lumen rating of 28k using 414 Watts.
This is not a single light source however. This light source occupies 9sqft instead of 1sqft, so we can say that every sqft is a light source producing 3200 lumens projecting vertically. Double it because half the light is being reflected down, so 6400 lumens.

In the case with this CFL setup the line of sight is vertical, because light source is always directly above.

23W CFL's don't produce very much heat at all, so the plants can be kept within 2 inches of the bulbs without browning. (Another thing to consider is that any HID will probably require cooling, so there is additional watts used beyond the ballast)

Again, with 3ft plants, this time the distance to the middle of the plant is only 1ft 8in.
Now subtract 1ft for standard lumen measure and the remainder is 0.7ft (8in).
6400 / (3.81 * 0.7) = 2399

If you consider that your plants are getting less light lower down, regardless if they are obstructed or not, it makes sense to grow many smaller plants instead of fewer larger ones. SOG and ScrOG are proven methods which are based on this fact.

Using CFL's you save a great deal of vertical space, and heat is very managable without major ventilation. This is perfect for SOG since you only need about 3ft vertical to grow a 2ft tall canopy. That's only an additional 2 inches to the bottom of the plant after subtracting the 1ft lumen standard measure. Additionally, with SOG you would be training the plants into a canopy anyways, so the bottom of the plant doesn't matter. With 3ft tall chambers, you can get 3 in a standard height closet, using the top or the middle for clones, so less space is needed for that one.

For a home grower at least, I have no doubt that CFLs are a better choice than HIDs

I'll let you know how my experiment goes anyways

 

My new growlux extended spectrum 400w HPS bulb claims its 58000 lumens .There less than 15 pound or 20 bucks. Check out http//www.theonlineelectricalwholesaler.com

 

check out www.Growtronix.com they have automation equipment that once setup will basically grow for you.