I grow pot every year since I was 14, now I am 50, and I love to grow plant of all kinds. they all look nice. green and healthy.
a lot of people that I know that grow ask me to look at there plants, and I tell them I am not a botanist, but I will look, and most of the problem originates from the same place, the tap water they are using.
if you are using water strait out of the tap "STOP".
first off it can causes lockout.
it creates a very deceptive looking deficiency.
purple in stems and leaves- looks like nitrogen deficiency.
yellowing of the lower leaves (or older leaves) working its way towards the top
before dieing completely- like a PH imbalance.
yellow spot, pail color.
you might think that you over watered it.
you might think that you need to ad Epsom salt.
you might ad some complete fertilizer.
but it does not help a lot.
it look worse each day.
it look like the whole idea about growing just is not right for you.
city water is chlorinated to kill germs and bacteria.(more in recent years)
cannabis is a chlorine sensitive plant.
continual use in planter shows up the quickest. in the ground might not be as saver, it might not be a problem at all if you prepare your soil sufficiently, but it might be a problem even if you do.
depends on how bad you water is.
first thing you need to do is fill a large cup half way up with fresh tap water,
put it up to your nose and sniff, what do you smell?
smell bad?
maybe like a cat box, or bleach.
that is the chlorine.
it will not harm you (much) it is in your pool, and the pool man always has to ad more.
just fill milk jugs(or any clear container) and let them sit in the sun for a few days.
it breaks down over time with exposure to sun and air.
keep in mind that the more surface area that is exposed to the sun, the faster the breakdown of chlorine will be.(so do not fill to the top, only fill to the narrow part starts, leave cap off)
in the meantime, use bottle water with a mild compete liquid fertilizer.