Thanks for the additional information. If the exit chamber is empty (or less than about 1/2 full) in any of your refill carts, you will want to plug the air vent hole and refill the cartridge using the vacuum method to refill the exit chamber with ink. The cartridges should not empty before the printer indicates they are low or empty, provided they were filled all the way in the beginning when the chip read full, and the chip is only reset after the cartridge is refilled with ink. If your LLK cartridge is emptying before the printer indicates, and/or you are experiencing flow issues in that position, you may be experiencing flow issues related to using carts for over a year, and may benefit from using a new LLK cartridge.
Humidity is very important, and we follow Epson's recommendations of maintaining 40-60% humidity levels in the printing environment for the best results with the printer, ink and papers. Low humidity can cause drying and clogging, especially if a printer is not used regularly (we recommend at least once a week). We constantly monitor humidity levels to maintain the recommended limits, by using air conditioners in the humid Summer months, and humidifiers in the dry Winter months.
We have detailed cleaning procedures, as well as a link to watch our video demonstration of these and several other helpful cleaning/maintenance tips with desktop printer modes, which you can read here: http://www.inkjetmall.com/tech/content.php?133-Printer-Preventative-Maintenance
I hope this all helps. Please let me know if you have questions or if there's anything further that I can help you with.
Best regards~ Dana