Try a #16 split case on a 16"-2' drop depending on the depth you are fishing. Trim you indicator up nice and neat with some scissors. Make it small; and add some float-ant to help it present.
Let your presentations play out. Try to maximize each try and let out line to last longer. One big no no is limit false casts with a passion. Shooting casts & reach casts are key techniques. Try to throw you fly to a dead zone above the area you are targeting. Think of that area as a dead zone. Also; practice letting the fly float down to the water like a parachute instead of slapping it (reach cast).
Slow drag or bump your fly before you reset your cast. It is amazing how many fish are sitting there ready to take.
In the early am throw olive midges with black beads-heavy (tungsten). It is insane how many midges are coming off in the morning. Just notice all the empty shucks floating on the water film.
If none of these work; throw a soft hackle fly that looks like a sulphur nymph and slow bump it (2-3") in the water like a streamer. You should catch 20-30 in a few hours right now with this method. However; it is a lot of work and you have to cast stealthy to not spook the area you are fishing.
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