The data-set includes daily uptake of dissolved inorganic phosphorus (DIP) and dissolved inorganic nitrogen (DIN) by U. lactuca (n=3) from the seawater, cultivated in a range of DIP concentrations (1 – 50 µmol · L-1) and a saturating DIN concentration of 5000 µmol · L-1 in a ‘pulse-and-chase’ approach (i.e. add a pulse of nutrients and follow their removal from the water over time) over 10 days. Additionally, conversation factors between surface area (SA), fresh weight (FW) and dry-weight (DW) of U. lactuca (n=60) are presented. Method of data collection: “pulse-and-chase” (i.e. add a pulse of nutrients and follow their removal from the water over time) under laboratory conditions.