悪水[akusui] undrinkable water
井戸水[idomizu] well water
一衣帯水[ichiitaisui] (being separated only by a) narrow strip of water
一水[issui] current (of water)
溢水[issui] inundation

飲水量[insuiryou] amount of drinking
飲料水[inryousui] drinking water
烏の行水[karasunogyouzui] quick bath
雲水[unsui] itinerant priest
塩化水素[enkasuiso] hydrogen chloride

皓礬[kouban] zinc sulfate heptahydrate
カリ明礬[karimyouban] potassium alum
クロム明礬[kuromumyouban] chrome alum

礬砂[dousa] size (solution for stiffening textiles, etc.)
丹礬[tanpan] blue vitriol
緑礬[ryokuban] melanterite (FeSO4-7H2O)