empty, full
glass, steel
4-foot, 50-gallon, 80-litre/80-liter, etc.
fuel, oil, oxygen, water
the hot and cold water tanks

gas, gasoline (AmE), petrol (BrE), propane (esp. AmE) (In the US, gas tank usually refers to the part of a car or motorbike that contains petrol/gasoline. In the UK, it refers to a container for a gas.)
holding, storage
a water storage tank

main
septic
fish

fill, refill
drain, empty
puncture, rupture
The truck crashed into a wall and ruptured a fuel tank.

clean, clean out
I cleaned out the fish tank today.

contain sth

in a/the tank, into a/the tank
Put a little fish food into the tank.

tank of
a full tank of petrol (BrE)
a full tank of gasoline/gas (AmE)

armoured/armored, army, battle

climb into, get into
drive
employ, use
an analysis of how tanks were employed on the battlefield

destroy

roll
Tanks rolled in to end the siege.

advance, attack
fire

battalion, company (esp. AmE), corps, platoon (AmE), regiment (esp. BrE)
commander, crew