Discussion in 'First Time Marijuana Growers' started by anaujiram420, Dec 6, 2003.

1. hello everybody!!

i am a beginner with two reflectors and two 60 watt grow bulbs from walmart. i have three plants in a closet that is 2 feet by 1.5 feet and about 8 feet tall. i also, have a few questions. first, is that enough light and is that enough space? second, i need a good explanation for lighting because i have read some other posts and there not that helpful. is 12/12 good for just starting them or no and how far away should the bulb be? right now its six inches away. third, when they first spout those two round leaves are first, should they fall off cuz mine did and are those the cotyledons? thank you.

2. >Need more light/ different lights
>Porbably not enuf space
>Put your lights on a 18/6 or a 24/0 light cyle till you r ready to flower
>The bulb spacing depends on what lights u have and how many watts
>Those r cotyledons

3. HIGH All, here is a good light guide by Jackerspackle.

A very general rule of thumb is that your garden needs 50 watts of HID lighting per square foot of illuminated area. This rule ignores the shape of your garden, so the following is really a better guide:

A 250 watt HID will illuminate a 2' x 2' garden.
A 400 watt HID will illuminate a 3' x 3' garden.
A 600 watt HID will illuminate a 3.5' x 3.5' garden.
A 1000 watt HID will illuminate a 4' x 4' garden.

From Jackerspackle, here's a different take on watts-per-square-foot/meter (WPSF).

WPSF assumes that the bulb's intensity is equal over the entire grow area.. in other words each square foot/meter receives the same number of lumens. But in reality light diminishes rapidly the farther you go from the bulb (1/4 the intensity for each doubling of the distance). So each bulb has a limited range, beyond which you do not have good growth.

For example, a growspace that's 2 x 10 feet would require 1000 watts if you go by the 50 WPSF guideline that's commonly mentioned.. But a 1000 watt bulb only covers an area about 5 feet across - meaning the edges of your garden will be dark.. A better choice in this case would be three 400s or two 600s.

Another problem with WPSF is it assumes all bulbs have the same intensity. But 1000 watts of HPS is not the same as 1000 watts of fluorescents or (yuk) incandescents. Fluorescents have their lumens spread out over a long tube and are therefore dim.. incandescents have the wrong color spectrum and are also dim.

Nor is a 1000 HPS the same as four 250 HPSs.. 250s don't have anywhere near the intensity needed to penetrate thick canopy or tall, bushy plants. (Don't even think about growing meter-tall plants with a 250.)

I could go on, but here's a basic guideline for lighting a growspace for good growth using common HIDs:

WATTAGE -- COVERAGE
1000 watt - 4 to 5 feet across (1.3 to 1.5 meters)
600 watt - 3.5 feet (1 meter)
400 watt - 2.5 possibly 3 feet (.8 to .9 m)
250 watt - 2 feet (.6-.7 m)
175 watt - small, less than 2 feet

These numbers assume you have a good reflector around your bulb and also reflective wall coverings. You can increase the figures a bit if using multiple bulbs, due to their overlapping effect. You can also increase coverage using a light mover...

4. 12/12 cycle is use for flowering..

for veg, u can run 18/6 or 24/7.....