I still say those numbers are minimum not Optimal. The math is still the same even though technology is improving the math is still the same. Flouriest light works it just does not put out enough for a good quality grow. For 1 to 4 plants for one person it's fine. You can't use CO² with fluorescents there is not enough lumens produced for the plant to process the extra CO².

For clones yes....for mothers...ok....for a first grow or two.....fine......for the long haul.....no way. The math does not support using florescent lights for quality grows. Plants stretch, buds are smaller, THC content is not as high in % VS HPS.

Lumens is a mathematical formula that measures the bulbs intensity at 1 foot. The color or type of bulb is not calculated in the formula I=L/D² Lumens received are a measured in watts-per-square foot or foot-candles. Calculating foot-candles or lux is a more accurate way to estimate the amount of light plants receive. This still only measures how much light you plants have available but not how much your plants use. Light diminishes exponentially fast!
The closer your plants are to the light the more lumens they receive the better they will grow, as long as the heat from the light does not burn the foliage.
Zandor Reviewed by Zandor on . lumens how many lumens would i need for my grow room my grow room is small and only growing one plant, im still researching a fluro for cheap i can purchase at ace hard ware or home depot and also what color white or blue Rating: 5