If your grapefruit are for personal consumption...I envy you. I can’t eat it because of meds. I miss it.
This is a tree that I grew from seeds - seeds out of a white grapefruit, a Duncan grapefruit, and it getting almost impossible to find.
According to everything I read on the web, I can’t expect any fruit until it is 5 years old or so.
If you have never had a Duncan grapefruit you would be AMAZED by it! But the qwest for seedless and red grapefruits etc have effectively mad Duncans almost extinct.