Hobby Print made a video on converting the Epson L1800 to DTF
The P400 has 14ML ink cartridges, and the 1430 has 11ML ink carts from what I can find, so not too far off from each other.
I used the refillable, and I remember immediately needing to use a CISS. If the CISS had ink in it before, it would probably be best to buy a new one. I guess you could flush it with distilled water, then flush out the distilled water with air and let it air dry. I Strongly disliked the Ciss, for already mentioned reasons, Plus the fact that it was almost impossible t