Problem here is that I build my own kits but it's not something I'd recommend to most folks because it requires a lot of painful lessons to get right (and I'm still learning) but so far I seem to have found that:
- Pressure needs to be kept minimal (ink levels no higher than an inch from the base of the printer) on a Canon CIS so a marriote bottle system is often the best approach or a raised printer to ensure correct pressures.
- Use of a single .5. or 1mm silicon grommet placed on top of the rubber grommet provides an additional seal against the cartridge exit port and that helps remove any air leakage
- When using sponged cartridges it's often a good idea to purge the cartridges completely to remove any algae, clogged/old/dried ink, etc... How you do this is a bit up to you but I've found a good hose combination that tends to blast through using tap water. This is a whole other topic however and you should check nifty-stuff forums for info on how you could handle the task.
Beyond that lot it's all down to accepting the warranty message and occassional chip faults.
Sorry I can't be much more help.
_________________
Printers: (Canon) MP500/830, MX700, iP4000/4200/4300/4500/5200, iX4000(A3) (Epson) C84/86, D88, CX6600, R285/800/1900 (HP) K550, K850, K5400, L7680