This tree was planted by my friend from Kiev , he was posting as Forward on the old forum.
He got the seeds directly from eyeckr. He still is taking care of this site (USDA zone 8B), some other hardy citruses like Changsha and Taiwanica planted by him are now mature trees giving abundant harvests.
The lady who talks about grapefruit has nothing to do with these trees, for her probably all that is not orange is a grapefruit