Settling particles in the water column of Lake Chala, a small (4.2 km2), deep (~90 m), and permanently stratified tropical crater lake at ~880 m above sea level in East Africa (3°19'S, 37°42'E) were collected monthly at 35 m water depth from August 2010 to January 2015 from mid-lake position. The collected material was allowed to settle and stored frozen after decantation of excess water. Prior to analysis, the samples were thawed, filtered over pre-combusted glass fibre filters, and the frozen and freeze dried. Bulk mass flux is expressed as mg m-2 d-1. The concentration of branched glycerol dialkyl glycerol tetraethers (brGDGTs) in the settling particles was analyzed using ultra high performance liquid chromatography-mass spectrometry, separating 5-methyl and 6-methyl brGDGT isomers.