3000 lumens sq. ft./32250 lumens sq. m. = Pretty Good growth. Enough light for the entire light cycle, although your yields may be lower.
4000 lumens sq. ft./43000 lumens sq. m. = Very good growth. Once you pass around 3500, growth rate and ability goes up fast.
if you read its sq. m and sq. ft please read and take in from the first post link this will fix your answer very easy
whitetop Reviewed by whitetop on . Another CFL Question I am using a 2'x4'x5' grow tent I have two 6500k, 3800L, 300W equivalent. I also have put a 2700k, 2800L, 150W equivalent in between the 2 blue spec lights. I built the light myself with the 3 bulbs wired in a row with indoor outdoor type fixtures. Is this enough for four plants to veg and when I start to flower will the three 150W, 2800L be enough. I have a tendency to over think the obvious so when I choose a bulb and figure lumen how do you figure what you need. For instance it says 6500K, Rating: 5