Tomato Bottom Rot

Also known as Black bottom, Bottom end rot, and Blossom End Rot.  Im sure there are more but this is what i have heard locally.

This is an example of the very start
of bottom end rot starting on this tomato.

So what is it?

well according to the Texas Aggies: Blossom end rot can affect fruit at all stages of development. The characteristic symptom is a progressive deterioration of the blossom end of the fruit, from a water-soaked appearance to a sunken, black, leathery lesion. While secondary fungal infections may occur, blossom end rot is a physiological disorder caused by calcium deficiency induced by water stress.

I can only speak to what I have encountered and I encounter it every year.  Every year the tomatoes I grow in pots get this.  Unfortunately I'm reactive instead of proactive.  So I wait until they show signs of bottom rot before I treat them.  Kind of as if maybe this will be the year that it doesn't happen.

Every oldtimer i ask tells me its missing calcium.  Just add calcium. So every year when it shows up, I add calcium and it always fixes my issue with bottom rot.  So lets go thought the simple step i do to help my tomato plants that have this.

1. First i take my bottle of Tums or other antacid relief tablets.   These are just about 100% calcium. 
2. I pour as much as i feel im going to need for this application depending on how many plants i plan to treat.
   
   
   
3. Smash it up to a powder.  I allow some chunks.  I think of it as a slow release form of calcium and the powder as a fast acting.
   
   
   
4. Last i just sprinkle it around the base of each tomato plant.  usually they are always the potted ones.
   
   
   
   
   
   
   

This is what i have been told and what i practice.  You can continue to let the grow and they are still edible.  Just cut the bottom rot off and the rest of the tomato is fine to eat.  In fact i made salsa the other night and i used 2 tomatoes that had bottom rot.  I just cut it back until it looked like healthy tomato.

Next is to figure out why the leaves are turning yellow and falling off on the bottom of these potted tomato plants.?!?