What could be the problem?

[bioman]

Was on the Weber the other day, at the Stoddard exit. I tried fishing nymphs,using a San Juan worm attractor and a green caddis larva dropper. No hits. Switched the caddis to a sow bug, one 4" hit it. Half hour later switched to stonefly attractor and zebra midge dropper. One 6" hit. Just after dusk I put on critter that looks like a brown wooly bugger with no tail. Got one 8" hit on that. The river was ankle deep in the riffles to thigh deep in the holes. My strike indicator was 5' above my fly. Most of my casts were quartering upstream and dead-drifting through the holes. I had one split shot, size B, 18" above the flies. Any suggestions that might improve the catch rate?
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