Deficiency? Salt Buildup? hmm......

Greetings,

Clones taken from female plant have been set in hydroponic set-up. Showing some signs but can't figure out for sure what it is.

Strain : unknown
Sex: all clones are from female mother plant
Age: Cloned Oct. 10th, set in hydro kit Oct. 21st
Water pH: Basic tap water @ 6.5
Temp: Was around 67 (too cold?), recently got it up to about 75 (too warm?)
Light: 600W MH
Nutrients: Used 1/2 strength Supernatural GRO AQUA 11-6-16 on Oct. 21st
Micro Nutes: Supernatural GRO AQUA contains 8% Ca, 2% Mg, 3.6% S, 0.01% B, 0.05% Fe, 0.03 Mn, 0.003% Mo


I'm leaning towards a basic salt-lockout as I noticed that where the water had splashed on some leaves and then evaporated, it left a bit of white spots everywhere. Notice also the tips of the leaves are slightly brown and crispy and curl upward as well as the lower leaves showing dark spots and contorting and twisting. Just not sure. I need to flush the system and re-apply nutes but if it is the water then I need to know if I should get some purified or distilled.

Any help is highly appreciated and responded to with +reps!

Thanks guys,
.:shalom:.

[pics attached]

Maybe a magnesium defficiency?

Looks a little short on potassium and just a little stressed out. Give it some time to straighten out on the nutrients. I'm not familiar with your line, so I can't comment on much, but more potassium would help if your temperatures are below 80.