Hi,

I am working on some 16S sequencing data, and seems some of them are low quality.

I am not sure how to set the trunc value in dada2.

qiime dada2 denoise-paired \

--i-demultiplexed-seqs paired-end-demux.qza \

--p-trim-left-f 0 \

--p-trim-left-r 0 \

--p-trunc-len-f 220 \

--p-trunc-len-r 180 \

--o-table table.qza \

--o-representative-sequences rep_seqs.qza \

--o-denoising-stats denoising_stats.qza \

Plugin error from dada2:

No reads passed the filter. trunc_len_f (220) or trunc_len_r (180) may be individually longer than read lengths, or trunc_len_f + trunc_len_r may be shorter than the length of the amplicon + 12 nucleotides (the length of the overlap). Alternatively, other arguments (such as max_ee or trunc_q) may be preventing reads from passing the filter.

What parameters should I choose?

Thanks for all your help !!