2 plants smae nutrients 2 different problems i think

Hi folks my first grow and first post.
Ok these 2 plants are in a 2 pot passive system.
PH is around 6 - 6.5

The first plant pictured has patches of paler green on some leaves and a few brown spots and the edges of the leaves are starting to turn brown also.

The second plant has droopy lower leaves that have curved downwards and the tips died while the new and upper leaves have a slightly crinkly look and the edges are curling up.

They are getting 18 hours of 250w hps and also have the 2 flourescent tubes i use for propagation standin up behind them to add to the spectrum of light they recieve.

Any idea whats causing the 2 different problems with the plants getting the same water?

is it hydro if so ph should be lower below 6

5.8 to be exact

if they are different strains than one might be a little fussy, example. this was @3200 ppm, i didnt know better @ 1st, but one of the plants loved it, look!

ph too high and looks like u r overnuting.

I have lowered the ph to as close to 6 as i could get it with some fresh clean water and flushed them. Have diluted the nuts a bit more seems following the label is a bit much for them still at the moment.
The newer growth at the tops is showing no problems now so fingers crossed its all going to be good again.

u may want to foliar feed the plants in the first set of pics- the 1st and 3rd one-with epsom salts