Digital BW, The Print

I'm having trouble with converting my 1200 to the new Piezotone inks 
using a CIS.  I had few troubles with the older inks.  Can't tell if 
it is ink starvation of just clogging.  I can get about six 
beautiful prints and then it starts to clog or at least does not put 
down enough ink.  Each effort to clean leaves a nozzle check that is 
worse each time.  It will print good for a few after letting it set 
overnight.  I have tried elevating the bottles and increasing local 
humidity.  None of these seem to be a fix.  Any ideas?