Q.Why Do The Tomatoes Only Get Bottom End Rot When They Turn Red
I have two plants in buckets. They are huge, healthy and loaded with beautiful tomatoes. I check them daily for rot and all is good; however, as soon as they turn red, they have rot. What am I doing wrong and how do I fix it? I fertilize and spray with a calcium mixture.

Certified GKH Gardening Expert
If you are sure that there is plenty of calcium available, I would look to environmental conditions. This article will help you to know what else can lead to BER:
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-blossom-rot.htm
This article will help you to grow tomatoes to their potential:
https://www.gardeningknowhow.com/edible/vegetables/tomato/growing-tomatoes-guide.htm
This link will take you to a free ebook that you can download on the subject of tomatoes:
https://blog.gardeningknowhow.com/ebooks/essential-guide-to-growing-tomatoes/