Digital BW, The Print

No, they don´t fit automatically, though inkjetmall  sends the 
7000 carts even if you order 7500 carts. You may use the 7000 
carts in a 7500 after having cut off the bottom nipples from the 
carts.  I use a sharp carpet knife for that purpose (take care of 
your fingers).
It works even with 3000 carts.
You may flush the printer with aqua dest, but I don´t know if that 
is good for switching from any ink to the new piezotones. 
Probably better you use a dilution of  amonia ( ? dont know the 
exact english term).
Bernd