Floating vs sinking a nymph

[DrNymph]

I've always been a nympher. Usually the high sticking sink em deep style. However, on my last trip to the upper delaware I experienced the effectiveness of fishing a floating nymph. And by this, I mean a non-weighted nymph.

My question is, when would you opt to fish a non weighted nymph vs. a weighted one?

 

[duckfoot]

For me, faster water = heavier nymph.

That said, I do tie pheasant tails without lead or beads and some with beads and lead.

 

[just_jon]

I regularly fish an unweighted nymph as a dropper to a mayfly before and during the hatch. Sometimes I grease the nymph and other times I grease the 6 inches of the leader 6 inches in front of the nymph. Greasing the leader has been more effective as it allows the nymph to sit in or just below the surface film. I've had evenings where fish killed the nymph. I've also fished a floating nymph when I cannot seem to connect with the dry.