My do-it-your-self terrarium

[Ross]

Lumens are rated at bulb surface (and is a measure/rating of output), Lux (or foot-candles) is measured by a meter at the subjects' location (as a measure of light per unit of area.) My meter is a calibrated Lux/Foot-Candle scientific meter so I trust its measurements down to decimal lux measurements. I use 4 tubes rated at 5000 lumens each. I measure 1800 to 2000 foot-candles at approx 20cm below lights. Conversion of foot-candles to lux is approx 1:10 (close enough).