Problems need advice....

Ok, I go away for a week and come back to a terrible mess. Leaves are turning brown and crispy at edges and rolling upwards, lots of leaves on one plant are shrivelled up and brown crispy ones just falling off and dead. In flower for 2 weeks before this happened. Growing tips around buds are crisping too and look like the whole plants are gonna go like this at some time. Some lower level plants have gone yellow and papery.
HELP! Have flushed out system last week and just filling up with water for now and no nutrients but looking like its getting worse now.

umm need more info...what lights you using..indoor or outdoor..what soil is it..did u water it for the week you were gone..and how old is it..vegging/flowering????

400watt bulb. hydroponics. yes it was waterred and fed before i went away and there was still some in there when i got back. They were only just put onto flower the week i before i went away.

o ic well im not very educated on hydroponics..do u have a timer for your light?...umm maybe it got to much light or to many nutes..not to sure buddy..more info and pics wud help