*Assuming CFLs for flowering with correct spectrum*
I agree with this guy. Specifically, what is needed is the most efficient setup for whatever resources are available. Some possible scenarios may include:
- space will only support small to medium heights
- heat is an issue (also impacted by space)
- noise is an issue (may run fan at a much lower setting...thus quieter)
- funds are moderately important (see below)
- the individual is not yet content with his "final design" plans
- looking to get started simple and ASAP (ready for initial action)
- somewhat new to the whole process
Assuming the above, for example, a *very* good setup absolutely exists - and could yield a lot more than most people seem to think).
A very efficient setup, for example, would be:
- the two 250W flowering CFLs mentioned
- two horizontal Bat-Wing style CFL reflectors (250W bulbs will not fit into the more classic looking CFL reflectors made by hydrofarm or sun, with the 200W CFLs being ok)
- 4" Fan/Filter combo
- 16 clones (8 per reflector) taken from same mother (to maintain consistent canopy)
- clones put into flower at same height of 5-6 inches
- focusing on just the tops, trimming lower branches if necessary (may or may not be)
This sea of green type style, in my opinion, is the most efficient design that uses the "big" type CFLs for flowering - the reflectors being necessary. Other sea of green type style variations are also quite acceptable: Ben's 4-top technique with maybe 4 clones per reflector instead of 8, screen of green, etc).
I guarantee that the outcome above would result in super dense and better than expected yields.
All that said, if there are no issues such as heat, space, funds, final design flaws, etc), then obviously HPS will be the most efficient (best yielding in this case) solution. This is the orange.