Casters on a Dour Stour

‪@MarkWintleFishing‬ For a change I'm fishing with casters on the upper Dorset Stour but for reasons unknown the river is in a very dour mood. Apart from small patches of bubbles and some very small fish topping there's little sign of better fish, and it takes a move to another swim to find something big enough to put a bend in the rod. It's possible the recent hot weather created an algae bloom which has died off which can cause the better fish to go off the feed.