I just wanted to share this information with the rest and also to have it here to remind me how I did it for the future. I just did conversion from aqueous to eco solvent ink on roland cj-400 and went perfect from start to finish. All I ever changed on printer is tubing on pump. Just put new tubes in pump and the rest I kept and didnt even touch including print heads, dampers and capping station. Let me walk you through the conversion. First I installed refillable cartridges and I put about 120ml solution made of 1 part all purpose Simple Green and 15 parts distilled water in each cartridge. Make sure solution is warm so it will clean better. I ran fill ink and let it sit for an hour. Than I added 60ml of hot solution again in each cartridge and ran fill ink 2 more times. Than I took out refillable cartridges and spill remaining solution that was left in them. Than I put about 100ml of butyl carbitol in each cartridge and shake them good so any remaining solution with mix with butyl carbitol. After that, I put them back in printer and ran fill ink 2 times. Than I took them out again and took out remaining butyl carbitol from each cartridge. Than I put eco solvent ink in each cartridge shake them good and put them back in printer. Ran fill ink again and that was it. Test print is absolutely perfect with all nozzles firing. Only thing that I did extra was to make new cap tops for capping station. Sponge in capping station has tendency to swell which can sometimes produce capillary action and you might end up with ink on the floor. Happens to me 2 times in the past. To prevent this you can make cap tops from wire mesh. I buy wire mesh for windows and move each wire to touch next wire. So basically its windows wire mesh but more dense. Than I pull sponge from the capping station and only one on the top. One on the bottom I leave it there. Than I cut wire mash with scissors to look about the same like sponge I took out. Than I install wire mesh on the capping station. Sponge I took out I throw away. So hopefully this trick will save you tons of money. I see new print heads are about $650 and new pump is about $50. Capping station is $180. You dont need to throw all that money.