I have a question regarding how much "suction" can be applied to the R2400 refillable cartridges when filling them. My kit came with 60ml syringes. Following the included instructions exactly, I put ~ 20ml of ink in the syringe, inserted it into the fill hole in the cartridge, and then applied ~ 10ml of "suction" many, many times to fill the cartridge. After a few cycles there was a lot of frothing of the ink and I think I was really just sucking froth back and forth most of the time. I then watched your video on filling the cartridges for a different Epson desk-top printer (can't recall the model) and noticed that you extended the handle of the syringe almost as far as possible (without the handle coming out) to generate the suction to fill the cartridge. It only took you two cycles to completely fill the cartridge compared to my 30+ cycles!
My question is: How much "suction" can I safely apply to the R2400 cartridges?