Digital BW, The Print

I have a new 4oz bottle of Eboni Black Ultratone 7 that was intended
for my recently deceased 2200 and a new 4oz bottle of Eboni Black K4
for my new 4800.  Can these two inks be mixed and safely used in the
4800 (hate to waste ink) or should I just discard the UT7 and proceed
with the K4?

Rich