You might have used growing soil, growing soil contains ferts in it. You really need to start with seed soil with perlite, then you can control the ferts & allow the plant to breathe a lot better.

Also tap water contains trace elements with chlorine, I recommend distilled water its only like 89ΒΆ a gallon at your local grocery store & its pretty clean of all trace elements plus no chlorine. But if you insist on using tap water, allow it to sit out for 24 hours to evaporate the chlorine.

When I first started my grow 3 months ago I made the mistake of using tap water & sprayed my leaves with it (foiler feeding as I found out its called), this left a residue on the leaves allowing the light to burn them.

Live & Learn :thumbsup: Ive only got 3 weeks left tell my first harvest!!!!