help required urgently please

[universally]

yellowing happening very fast would apriciate some help please have a look at the pic [attachment=o224865]

[Rubberbubbler]

Its hard to tell for sure that pic is not very clear try taking a pic without the light on. it may be a magnesium and calcium deficiency or nut burn get a better pic and fill out the trouble form.

[killerweed420]

Yeah it looks to be fatal. Looks like all the leaves are doing it.

[oldman420]

looks like lockout to me.
get us some more info
soil or hydro
whats the ph of your media
did you check for parasites?
looks like nutriant lockout to me most likely ph induced.
best of luck to you

[irydyum]

Can you get a pic under regular light away from the HPS? That should help get rid of the lines, and let us see what color the plant actually is.

Get some info up asap man!! We can't help without knowing what's going on in ur grow.

[michaelpeg]

looks to me like magnesium or zinc defficiency, probably due to ph.