We ran last year with a 90 gallon watertank that weighed about 1000lb loaded. It has a lift pump, then the factory pump. It also ran 2 oil squirters per piston.
Might sound a bit crazy, but we were adding 1000lb worth of steel ballast anyhow, which overloaded the trailer axles. So this way, we tow a 1000lb lighter, then fill up the tank local, and dump it to go home. The tank has 9 chambers of 10 gallon each with non-aligned entry and exit ports in each one. This was to resist sloshing. That much water could upset the truck if allowed to shift during a fishtail.