Cannabis Seedling Issues

could be the fan.. don't use rain water. It's often not a healthy option due to local pollution -- that can carry 100s of miles from the source. Often too acidic, which can also cause growth issues. "Natural" isn't all people make it out to be more often than not... most 'natural' stuff out there is harmful to us, lol. uranium is natural. lead is natural. cyanide is natural.. anthrax.. et al It's not even a mild correlation. Move the fan further away.. a little occasional jiggle is all you need to see. that means air is flowing through and that's plenty to promote a strong stem, too. As long as the soil isn't extra hot, should be fine... for shits and grins, pH test your rain water next time.. even if okay, tend to have all sorts of dirty shit in rain form atmosphere. we've totally shit the bed (earth) as a species, lol.