Three　identical　lab-scale　biofilters　were　employed　to　optimize　the　start-up　process　for　simultaneous　removal　of　iron　(Fe),　manganese　(Mn),　and　ammonia　from　potable　water　supplies.　Nitrifying　sludge　and　backwashing　sludge　containing　Mn-oxidizing　bacteria　(MnOB)　were　used　as　the　inocula.　The　start-up　strategies　consisted　of　simultaneous　and　separate　inoculation　of　the　two　kinds　of　sludge.　The　influent　Fe　was　removed　immediately　when　the　biofilters　began　to　operate.　The　effects　of　nitrification　for　ammonia　removal　showed　no　significant　difference　between　these　biofilters.　However,　the　beginning　of　Mn　removal　with　separate　inoculation　was　faster　than　that　of　simultaneous　inoculation.　The　Mn　removal　can　be　described　by　using　first　order　reaction;　and　the　k　(rate　constant,　min(1))　values　were　0.147　+/-　0.007　(mean　+/-　standard　deviation)　and　0.153　+/-　0.006.　Besides　the　commonly　reported　MnOB　genus　Crenothrix,　MnOB　genera　were　also　found　to　be　related　to　the　genera　rarely　reported　in　the　potable　water　treatment　systems.　(C)　2014　Elsevier　Ltd.　All　rights　reserved.