1st time grower here and I have a few white widow autos in week 2 from seed... Water only when soil gets really dry like a last minute water to prevent bugs. I am seeing brown spots starting to grow on some of the leaves. What is the cause of this? The plants have been on a 24hr light cycle for 1 week, now week 2 I moved to 18/6 lighting. I'm Using a SF4000 Spider Farms Led grow light and I only feed the plants bottle water only. Is this normal for spots like these to show up in the early stages of the grow? if not how can I fix? Thanks for the help.