Quote Originally Posted by Pedro de Pacas
That's the thing: I have CFL's coming out the yin-yang from previous grows, I wanted (as an experiment) to do 12/12 from seed using the same lights...I have read about growers using HPS throughout rather than switching from Fluo or MH during vegetative to HPS for flowering...

Not having a proper light fixture for my 125 watt CFL doesn't help matters either. But...given the shaky start this grow is having, perhaps switching to CFL until sexing would be the right thing to do? :wtf:
No I don't think you have to wait that long. My first grow I used a 21w flouro for less than a week just until it the new leaves came in a little, then put it under the hps and double the normal height. Technically, you could sprout them with the hps, but they should be pretty far away, I'd say at least 2-3x farther than normal. Then, gradually, lower the light. It's not very efficient, but it should only take a couple weeks until you get the light to the final 50cm mark (less if you have a cooltube, of course). The 50cm is just a recommendation from a friend. Without the cooltube I kept it at 40cm from the light, max.