Digital BW, The Print

I have an empty set of 7000 cartridges. I want to fill them with MIS ink and use 
with an Epson 7500 printer. Is this possible? Do the carts for 7000 fit an 7500 
??

Do anyone know if I can use distilled water in the carts for flushing the tubes 
before installing a different type of ink?

Bjorn