i've got "a whole lot of shaking going on" in my tank too.
have they dug any holes in the sand yet ?
i've got huge excavations in my tank,and thankfully the Very large slate was placed on
rocks on the bottom of the tank,otherwise i dread to think what could have happened,
the plants are pretty much untouched,but they have never been ones for
javer fern or vallis anyway thankfully.
yu may find that one goes off it's food,so appears to reluctantly feed,and that will be when
they're holding fry,as the time goes along,as the fish opens its mouth,you'll see
tiny dots in it's mouth,that will be the fry,make plenty of rocky places for the fry to find hiding places,
as the other fish will eat the fry if they see them.