Grounding fuel tank

[Zebra]

Where did you ground the fuel tank too. I'm thinkin right to the neg. post on the battery and be done with it. The fuel tank i had made has a tab for grounding forward and aft. I dont think the old tank was grounded at all found no wires from it going to any ground. Fuel sending unit has a ground does that do the job or should i use one of the tabs to a ground.