sick leaves

[jettazz]

the fan leaves start by getting brown tips and rust colored spots and end up looking like the real ugly pic and then fall off.
info:

water 6.2 ph (tap)
nutes 20-20-20 once every 2-3 weeks at 1/4 strength (havent nuted since I went to 12/12)
normal soil (no ferts mixed in) mixed with perlite
2 fans blowing when lights are on
plant is almost 2 weeks into flower


If more info is needed let me know

[chonged]

looks like a magnesium deficiency, give them nutes but at quarter / half recomened dosage

[jettazz]

I can use epsom salts for that right? if so how much/gallon

Also I just purchased some superthrive and hopefully it'll help

[seedbare]

dont use tap water water less often, that far right plant been sexed?/ looks like male plant.

[jettazz]

The plant is most definately a female, notice the white hairs all over the place, I'll probably buy a water filter this weekend. My local tap water has flouride in it and maybe that's causing a nute lockup or something.

[dangerousmathed1981]

yeah that is definately a female, you should switch to some kind of super-bloom fert. that is higher in potassium(k), females need more during flowering to promote bud development. a (k) deficiency will cause the leaf margins to burn and curl up.