Yo man, Here's my power set up
250 alt. - Yellow top optima - 200a fuse - isolator - Yellow top Optima - both amps
1st batt: Power from alt to battery and then of course it is grounded.
Power wire is run to the fuse to the rear battery. two power wires are run from that battery to the amps, one to each amp. That battery is grounded to the car