Liquid supply device and liquid supply method

A liquid supply device comprising:

• a cartridge mounting portion configured to allow a cartridge to be mounted therein;
• a tank;
• a head configured to eject an ink supplied from the tank;
• a first liquid supply channel connecting the cartridge mounting portion and the tank;
• a second liquid supply channel connecting the tank and the head;
• and
• a controller,
• wherein the cartridge includes a first cartridge storing the ink and a second cartridge storing a preservation solution, the first cartridge and the second cartridge being separate from each other, and selectively mountable in the cartridge mounting portion, and
• wherein the controller is configured to:
• cause, in a recording mode, the ink to be stored in the tank such that a maximum liquid level of the ink is a first liquid level;
• and
• cause, on condition that the controller receives a command of a preservation mode, the preservation solution to be supplied from the second cartridge to the tank through the first liquid supply channel so as to reach a second liquid level higher than the first liquid level.