Attached the quotation for ink tank with cover, prepared with second hole for viscosity sensor.
I am just wondering how he can work with a second ink tank without a ink pump and without injection system.
Otherwise a color change will be not possible.
In any case if you need a complete ink pump with (tank, motor, etc) and injection system will be 1980 Euro (tubes included), which is much better.
attached also the electrical diagram, this should be also in the manual which was delivered with printer
if you need more information, please don´t hesitate to contact me at any time