The examples provide a fluid ejection apparatus that includes a fluid slot; a passage, a drop generator and a fluid circulation pump. The passage has an inlet connected to the fluid slot and an outlet spaced from the inlet and connected to the fluid slot. The passage as a first portion extending in a first direction from the inlet and a second portion extending from the first portion to the outlet in a second direction, opposite to the first direction. A filter is within the fluid slot across the inlet.