Digital BW, The Print

I'm currently using the Cone Piezo B&W ink cartridges in my Epson 
1200.

I would like to try the MIS FS inks in cartridge form (will continue 
using the Piezo software).  Does anyone know if I will need to flush 
the Piezo ink before using the new MIS cartridges?

I'd appreciate any recommendations based on your experience.

Thanks,
David Cook