You have created a hostile environment for the worms. Please don't add more worms until you fix the problems.

The first thing you need to understand is the difference between what we call 'bedding' and what we call 'food.' Bedding is anything that is high in carbon: paper, cardboard, coir, dry leaves, etc. Food is anything that is high in nitrogen: kitchen scraps, coffee grounds, etc. Mixing coffee grounds with shredded paper does not produce bedding. It adds food to bedding.

You are grossly overfeeding. I would put enough bedding in the bin to absorb the excess water, and offset all the coffee grounds. Then stop feeding for a few weeks. Putting dirt in the bin was a mistake. Too late now. Add lots of bedding, and you should be OK.

Stop adding Tums. Instead add more bedding.

I like what you are doing with the coffee grounds. My worms seemed to ignore them until they started to form the white fungus layer on them. The only other thing I would do is add more bedding to offset the nitrogen in them. It is probably the nitrogen, and not the pH, that is causing your problems.

Adding another tray will only help if you create a better environment at the same time. Your half-finished compost makes excellent bedding. Since it is already C:N balanced, you really don't need additional food. The worms will increase to fill whatever space they have, assuming a healthy environment. Mix your compost with shredded paper or cardboard, add enough water to make it moist, but not wet, and you will have great bedding. You have already seen that adding food also adds moisture, so you need to be careful not to let things get too wet.

So: 1) more bedding, 2) less moisture, 3) no more dirt, 4) slow down on the feeding.

Worms are pretty forgiving. I think this is a mess that can be fixed over time.

Grab a home brew, sit down and put your feet up, mate. This government shutdown might take a while. No doubt you'all in DC are going to need a lot more entertainment than worm sex to stave off the boredom. I'm going to need a few more brewskies before tackling this one.

I only used dirt in the bin with ENC, which is separate from the Worm Factory with Red Wigglers. They seem to like that fine.

I figured that coffee was relatively benign over time--it won't ferment into alcohol, and if I pre-compost it it shouldn't heat up on its own--so it seemed like a good food source. You indicate that mixing compost with paper produces an ideal environment that doesn't require additional food; by that logic, if I let the coffee grounds pre-compost for a couple weeks, I should be able to use them as a food source without worrying about overfeeding. I'm getting mixed signals here; please clarify.

I was hoping on adding another tray with more worms both so that the additional worms could more actively deal with the excess mass of coffee grounds and so that the new tray could be less of a disaster to provide refuge. This time it'd be pre-composted (not fresh, hot, wet) coffee grounds mixed with coir, peat (the worms come in peat), and plenty of paper. I just happen to have access to a lot of coffee grounds. Would it be better to stick to just coir and paper?

You need both bedding and food. Coffee grounds can be good food if you do exactly what you are doing with them. The problem I am seeing is that you are adding the food faster than the worms can eat it. Let the worms catch up. When they do, you will probably need more bedding, since they also eat the bedding as it decomposes.