you should be able to tell, if a leaf looks like its all yellow and dead, sometimes all u gotta do is touch it and it falls off, thats actually a healthy sign. its normal for some leaves to die off over the life of the plant. if a VERY gentle tug on suspect leaves doesnt pop em off, they should stay. obviously completely dry should be removed, it just promotes better airflow.
I just noticed something with my clones that have been transplanted. if they are kept within 4 inches of the cfl's they are bushy, any further away than that, and they start looking a little stretchy. The 26w cfls get to hot to touch the plant, but T8's can rest right on them.