meetzu
Well-Known Member
Alright, I have done the math and typed out lengthy posts answering the same question with a few variations each time. I figure I will put it here, tag the hell out of it and hope people search and find it.
If you are looking for the basics on lighting, go here.
First we will start with this chart. It's pretty self explanatory; it shows the amount of foot candles received by the plants at a given distance from the bulb. In my opinion this is a better way to judge light needed over watts/lumens per square foot due to the inverse square law (light dissipating over distance) .
Now for the math to figure out the distance your bulb is from the edges of your grow area. To do this use the Pythagorean Theorm (a² + b² = c²).
"a" will be your anticipated light height. This will vary based on the wattage and what kind of cooling you have.
"b" will be 1/2 of the area that your entire grow space will cover. It is half of that because your light will be in the center.
"c" is what you are aiming to figure out as it is the distance that will change based on the first two variables that you will already know. "c" is then compared to the first chart to find if the plants at the furthest distance of your grow space will be receiving adequate light. Corners of square grow areas will be further from the center than the center of the side walls.
You can also use this equation and the chart to figure out how high your light can be while still providing adequate light. If you have a predetermined grow area then you know "b" and you can choose a value based on the chart above which will be the threshold of your light's reach ("c") and then find the maximum height ("a").
The equation for that would look like: c² - b² = a² where "c" and "b" are the known values from the paragraph above.
So.. hopefully some people will find use in this. Sorry if it seems confusing, I tried to make it as easy to understand as possible. Cheers.
If you are looking for the basics on lighting, go here.
First we will start with this chart. It's pretty self explanatory; it shows the amount of foot candles received by the plants at a given distance from the bulb. In my opinion this is a better way to judge light needed over watts/lumens per square foot due to the inverse square law (light dissipating over distance) .
Now for the math to figure out the distance your bulb is from the edges of your grow area. To do this use the Pythagorean Theorm (a² + b² = c²).
"a" will be your anticipated light height. This will vary based on the wattage and what kind of cooling you have.
"b" will be 1/2 of the area that your entire grow space will cover. It is half of that because your light will be in the center.
"c" is what you are aiming to figure out as it is the distance that will change based on the first two variables that you will already know. "c" is then compared to the first chart to find if the plants at the furthest distance of your grow space will be receiving adequate light. Corners of square grow areas will be further from the center than the center of the side walls.
You can also use this equation and the chart to figure out how high your light can be while still providing adequate light. If you have a predetermined grow area then you know "b" and you can choose a value based on the chart above which will be the threshold of your light's reach ("c") and then find the maximum height ("a").
The equation for that would look like: c² - b² = a² where "c" and "b" are the known values from the paragraph above.
So.. hopefully some people will find use in this. Sorry if it seems confusing, I tried to make it as easy to understand as possible. Cheers.
