Have you attempted to print out a nozzle check pattern? Is there any air inside of the tubing? Whenever you are experiencing quality issues we would then recommend priming the cartridges. We have created two videos which show the priming method being done and I will include the links below.
If you still have the caps that came installed onto the cartridges you would be able to re install them onto the cartridges and use a needle and syringe to withdraw ink from the end of the cartridge. https://www.youtube.com/watch?v=2ccxMBaSUQI
2nd priming method. If you do not have the caps that came installed onto the CISS https://www.youtube.com/watch?v=fg2lk4lou2Q
The first priming method is the most effective way. I would recommend printing out a nozzle check pattern and comparing the quality before and after to see if it has improved.