What to place in the LL Black slot -- epson 7880

I havebeen running piezo pro inks for about a year in my 7880, with 7 inks and just left the LL Black Epson cartridge in the printer (the inlkchannel not being used). It has run dry. Should i use a refillable cartridge with the correct chip with just piezo flush in the ink cartridge for LL Black?

Yep. Piezoflush is what you want in there to keep that channel alive for future use.

Sorry for the late reply,

best regards,
Walker