6 week old auto flower BB leaf issues

I have a BB auto that I have had to leave for about 5 days to go out of town. Before I left I flushed them with Ph'd water, forgot to use cal mag. I came back home to 2 bone dry buckets but plants still growing but the leave just do not look right. I am growing in coco and perlite and using cns 17 veg and bloom.

Well for one I hear that coco is almost impossible to grow in for a lot of growers, but that looks like a nitrogen deficiency or maybe sulfur

ok thank you