Yeap , is possible to add another algorithm , but i suggest to talk to an experienced developer first.
my current developer can merge multi algos im going to try x11 next and see how it goes coin we are working with is gytecoin.
Groestl sounds like a good idea after I try x11
it may be
sha 256
scrypt
X11
x15
and Groestl (not sure if my developer can make that coin yet will have to ask)