During a 35 day long experiment, the prokaryotic community of four replicates was sampled daily to gain insight into short term community flucutations and succession during highly productive and North Sea typical spring bloom. Samples were fractionated (0.2, 3, 8 µm) and 16S amplicons of the free living (0.2µm) and small particle attached (3µm) samples were sequenced using a V4-V5 primerset. Mock communities were included in two of four seqeuncing runs to ensure seqeunce quality.