Embodiments of a fluid tank may comprise tank system that comprise a level indicator system useful for measuring the amount of fluid in the tank and a floating suction tube useful for filling or removing a fluid from the tank. Further in some embodiments, the tank system may be installed in a single port on the fluid tank.
Some fluid tanks comprise stratified layers of different fluids. A buoyant portion of the suction tube can be constantly submerged in a desired portion of the fluid, allowing the desired fluid to be removed through the inlet port. The level indicator system may include a cable system connected between a biased level indicator that moves in conjunction with the movement of the buoyant portion to indicate the fluid level. In the alternative, the level indicator system can include sensors on the suction tube to remotely monitor the level of liquid in the tank; sensors include inclinometers, accelerometers, sending units, and magnetostrictive sensors.