We have a grapefruit tree that we have concluded is at least 65 years old. It used to produce beautiful pink grapefruit.
For the past 2-3 seasons it has really started to struggle. The tree is thinning out, the fruit is small and not tasty.
I've heard from some that the tree is just dying, and there is nothing I can do. I've also heard that it could be "sick" and it should be able to be remedied.