Diatom and associated water chemistry data for 30 small ponds & pools from SE England collected by, and described in Bennion (1994). Dataset is a list with the following named elements: (spec) diatom relative abundances for 48 selected common taxa, (env) lake names, UK GB grid references, lake depth (m) and mean lake-water chemistry. Units are ueq/l except pH, conductivity (uS/cm), alkalinity (meq/l), total phoshporus and chlorophyll-a (ug/l), and nitrate (mg/l). Column names in spec are short, 6-character alphanumeric codes for each diatom taxon. Ponds$names contains the full names for each taxon, in the correct order).