So exactly how many lumens do i need for 2 plants?
According to google, only 5000 per sq ft is needed, so with 2 8800 cfls, it should be enough.
A good rule of thumb is somewhere between 40 - 80 watts per square foot. Here, I borrowed this from Fuzzy Duck over on 420 magazine:
Not that lumens has any thing to do with plant growth as its a measurement of light visable to the human eye only !
Its more about PAR, light spectrum & qualitie of it.
But anyway in a nutshell…
Lumens per square foot:
Minimum amount of lighting needed is around 2000 lumens per square foot.
(Two – 23 watt CFL’s, per square foot*)
Mid range is around 5000 lumens per square foot.
(Three - 23 watt CFL’s, per square foot*)
Optimal is 7000-7500, or higher, lumens per square foot.
(Five – 23 watt CFL’s, per square foot*)
*I’m only using CFLs as a reference here, with the assumption they’re kept at a distance of 3 – 5 inches from the plant. It is important to understand that the “penetration” (the farthest measure that quality light reaches down into the plant canopy) will at best be only a few inches deep.
Watts per square foot (wattage per sq ft WILL vary by light source):
Minimum wattage per sq ft.: 30w
Mid Range wattage per sq ft.: 50w
Optimal Range wattage per sq ft.: 50-80w