Hi again Mistaswift. Im pretty sure it's not spidermites that are causing the damage I can see in your pics. The white spots are on the leaf tip marhins and from your description.. it seems to be moving up your plant from the bottom. Spidermite damage creates a random pattern of tiny white flecks on the leaves where the little bastards have sucked the chlorophyl from the leaf from the underside.

Im no expert and I'm suprised a few of the more experienced growers on here haven't nailed it for you. The symptoms look disttinctive to me but I've never come across them personally.

Ive done some searching and the thing that seems to match ur problem is a Zinc deficiency.
Quote:
ZINC (Zn)
White areas form at leaf tips and between veins. Occurs in alkaline soils. Zn deficiency can be treated by burying galvanized nails in the soil. Chemical fertilizer containing Zn can also be used.

Your soil is ph 6.8 you say... which is not a major issue. A ph of 6.4 may be better but I cant see that bieng the prob. I'm wondering if there is any Zinc in tap water and it is bieng removed by the filtration. Or any other metals for that matter.

We need an emergency 'call stinkyattic' button on these forums. She would get to the bottom of it.

Can u take some more pics that show the 'little white spots everyehere' you mentioned in the last post.

We will get to the bottom of it eventually :rasta: