OK thanks, what I've done is I've taken my working multiphase model and changed it to species:



I've set the hydrogel phase (i.e. 99 % of my mix) to this species, and I still patch the calcium section (1 %) at 0.5 in initialization. So I've gotten this after 60 seconds of mixing (I'll have more running overnight, this is just what I started for now):



Do I need to modify any of the settings I've shown in the species window (or elsewhere in Physics/User-Defined), or am I good with running a long section of these settings?