31000 lux = 20 lumens per square inch

I'm not exactly sure I explained this correctly. I moved my phone vertically closer to the lights, where the plant was elevated to, then took the reading.

Hey,

Well your right, but also since it is a single source of light, that more than likely determines the lumens per area, maybe this link will help,http://en.m.wikipedia.org/wiki/Lux

also, the phone apps you can get arnt very accuarte when you use them next to a photometer. They give a rough guide though.

Take care.

LUX > lumen anyway.

32k can be a lot. What kind of light are you using?

lux = lumens/square meter

1 foot = 0.3048 meters

1 square foot = 0.3048*0.3048 = 0.09290 square meters

31000 lumens/square meter = 0.09290*31000 = 2880 lumens/square foot

Incidentally,

lumens/square foot = foot-candles