•5 filters were compared to find the most effective for an As-affected village.
•Iron-based filters can remove As, but removal is affected by filter design.
•Nails placed in biosand filter sand were more effective than those placed above.
•The arsenic biosand filter (nails above sand) rarely removed arsenic to <50 μg/L.
•The biosand filter with embedded nails removed arsenic to <50 μg/L for six months.
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