Multiple tanks and GFCIs on one circuit

[boca rat]

I have two tanks in two rooms, that I wired with a GFCI each. Both are on the same circuit. With hingsight this was redundant, right?

GFCI on tank 1 started tripping recently (anything from tank 2 plugged into any outlet in that room, not just the GFCI) which made me think....

1) Do I need both tanks on GFCIs when on the same circuit?

2) If not, where is the best place to put the GFCI assuming tank 1 is closest to breaker box?
a. on tank 1
b. on tank 2
c. between breakers and tank 1
d. after tank2

Thanks!