You can check the approximate ink levels and the approximate service life of the maintenance box from the printer's control panel. Select 
on the home screen.
The following indicates the amount of free space in the maintenance box.
A:Free space
B:Amount of waste ink
You can continue printing while the ink low message is displayed. Replace the ink supply unit when required.
You can also check the approximate ink level and the approximate service life of the maintenance box from the status monitor on the printer driver.
Windows
Click EPSON Status Monitor 3 on the Maintenance tab.
If EPSON Status Monitor 3 is disabled, click Extended Settings on the Maintenance tab, and then select Enable EPSON Status Monitor 3.
Mac OS
Apple menu > System Preferences > Printers & Scanners (or Print & Scan, Print & Fax) > Epson(XXXX) > Options & Supplies > Utility > Open Printer Utility > EPSON Status Monitor