replace it. period.

you also have a Mg anode rod in it to contend with. once that is
gone, you get electrolytic corrosion that makes a blowout a matter of
time. its not a question of "if". its a matter of "when."

as far as softening goes, (the quality of the rest of the pipes in
your house (especially the hot water pipes) can be just as suspect as
your hot water heater) it's cheap insurance. it preserves your pipes
and your hot water tank. and it doesn't use that much water on
recharge. it exchanges out Ca, Mg, preferentially, and Fe and Mn if
you add a calcium chloride pretreatment tank.

they are sized based on how much water you use and how much and what
kind of hardness you have. adding on a softener now can bring your
pipes back over time, if they've narrowed from deposits.

you'll find that your soaps do a MUCH better job cleaning. at a much
lower usage rate.

no. i don't work for culligan or kinetico. i lived with
unbelievably hard water in IN and CT before i went the softened water
route here in NH. there's no going back.....