Hey Ziggy...
can I see the entire plant....

How is your NEW growth... at the top of the plant?

Dogg has a great point... PH fluxuation can make plants act a bit funny...

Are any of your stems red?

You are growing Hydro...? You should consider a one day flush.. but I would reallylike to see the entire plant..

my gut says it is nothing to worry about..

: )