My Canon i455 takes BCI-24 cartridges. I have refilled them using ink
from InkReloaded for the past 2 years, and, whilst I'm happy with the
colours (compared to the original Canon cart), greys have a distinct
greenish hue.

Any recommendations for good quality refill inks, especially the pigmented
black, for this type of cartridge?

Also, provided I don't let the cartridge ever dry out, does the sponge have
a life after which refilling is no longer effective?

Many thanks

Martin