Problems with QIIME2 view

When opening fastq files,all of the quality line of the offline data are F, and this is the case for each sample. Is this normal?

qiime tools import --type ‘SampleData[PairedEndSequencesWithQuality]’ --input-path manifest_fix.csv --output-path paired-end-demux.qza --input-format PairedEndFastqManifestPhred33V2

qiime demux summarize \

–i-data paired-end-demux.qza
–o-visualization paired-end-demux.qzv![2021-04-02 18-04-01 的屏幕截图|690x431]

The result of qiime2 view is shown in the figure:(upload://puS8MOP4vvgbbIBk2QzYdnSNI0Z.png)

Is this normal?

Thank you for all the answers!

Hi @lys - it looks like your attachments failed to upload for some reason, can you please try again? Thanks!

Hi, thermokarst!

This is a screenshot of the sequencing results. The letters in the quality line are all F and almost all samples are like this!Is it normal? Why dose this happen?

Thank you very much!

Actually, I see other scores in there, as well: F, ,, :!

Maybe? Its hard to say without know what sequencing technology you used, preprocessing steps applied, etc. I think if you want a concrete answer, you should check with your sequencing center - they should be able to tell you more about these data.