I know you're just trying to help, but this is misinformation.When using CFL's, they need to be placed about 2-3" away from the plant (there is a narrow sweet spot), put the bulb too far away and ur plants won't even grow!
My cabinet has lights at a fixed height of 23" above the ground.
Here are some pics of my plants. The first two sets of plants were flipped into 12/12 between 2" and 6" tall. They did not grow to their full potential. Hence, 6"+ is the new rule. The Dr.'s "sweet spot" is referring to finding the perfect height at which to induce flowering, that way the plants will grow all the way up to the lights and then STOP, thus maximizing the potential of that individual plant's harvest within it's own footprint. (No lateral branching, just one "bud stick"):
These last three pics are of plants that reached the 23" tall point. (the one on the right is the same as the one on the left. It's the same plant after revegging. Say "high" to mama.) Clearly, they grow just fine. When my plants go into the flowering chamber, their average size is 6". They're in 6" pots, so that means that when they begin the flowering cycle, they are about 12" tall. That means that the CFLs are at least eleven inches away! My plants are basically sticks of weed (ala dr. bud) that grow fantastic, frosty, sticky buds all the way to the base of the plant. So the lights are only 2"-3" away from the plant tops in the last weeks of their lives.
I humbly disagree.