leaves dying off, black tips

unknown strain, under a 250watt 5600k cfl, 18/6 lighting with soil temps around 25 degrees. have been using ph'd water around 6.7 with cycogrow platinum every so often, just a drop.
in soil mixed with perlite.

leaves have been getting worse and starting to worry that it might spread to the top, very new to growing so any help would be great.

also have an autoflower ak47 that has started showing its sex, although as you can see there are very few leaves. again any help would be great.

hey

this is only a starting point for u

how much watering have u done .............amount and time
have u tested the the soil ph...............(little buddies in the ground can alter one way or other depending on the amount and the feed) learning this lesson myself

my guess is u are watering to much (to much moisture is in the soil and the N is not aborbing all that well)................your light is good better then what i started with but the pot u have is a standard one that does not allow air in so what wetness is in there stays due to the pot