G-man, I don't want to start a battle here, but it sounds like your trees are stressed..the best thing to do for stressed trees is using Superthive.
Believe me, I have used it on plants I thought dead, and within days they resumed health.
I know some ppl here think it's snake oil, but there's others who use it religiously.
You can go to Superthive's website and get a sample bottle..I think shipping is .60..Why not give it a try? You've nothing to lose except sixty-cents..If you don't think it's helping then refrain from using..Toni

gman, let me ask you a question. From your first set of pictures a week or two ago, some of the leaves had dark green and also yellow spots. Did you foliar spray the tree'a FOLIAGE with an iron chelate or other form of iron? After you respond we can go from there. - Millet

Millet, after about a week of the dropping leaves I picked up some Earthjuice Microblast and applied a foliar feeding to the leaves (after diluting per mfr instruction). I did this to all three of my trees and didn't really notice anything positive or negative on any of them. It certainly didn't stop the leaf drop on the Meyer.

Actually, this past weekend I bit the bullet and just went ahead and did the transplant to the CHC/peat mixture. Here are some pictures from that operation.

The root ball:

{{gwi:616095}}

The full tree:

{{gwi:616097}}

I had a great deal of difficulty getting all the soil out of the root ball, but finally managed. The root ball is very full and dense, for whatever that's worth. Anyway it's been a couple of days now and the leaves are still dropping. They all have a kind of circular discoloration- here is a closeup:

{{gwi:616099}}

What's a little perplexing (to me anyway), is that while the older leaves are falling off, there is a fair amount of new leaf growth at the tips of many of the branches:

{{gwi:616102}}

Still not sure what is going on or if the tree is going to make it. There are still about 20 or so decent sized fruits on the tree, so I'm sure hoping he makes it!

Gman, products like "Earthjuice Microblast" (which I never even heard of), "Superthrive" and the whole lot of "Miracle Cures" (which there are many) are as you probably already suspect, never ever used, nor are they even recognized as valuable resources by commerical citrus producers nor by the citrus industry in general. They are never used by them, and the reason is they don't work. A MOST intreguing aspect of your tree, is that for a tree going through some sort of stress resulting in leaf drop, the tree still looks rather healthy. I must admit it has me puzzled. As you live in California, a citrus producing state, there is always the chance that the tree has a foliar disease. However, I think the tree's problem had something to do with the growing medium. The tree had a lot of roots, but out of all the root structure I only seen one (1) new little white root tip. Only one! All the roots were only the older roots, having the light tannish brown coloration. There has not been any new growth. I believe if you had not transplanted the tree the leaf drop whould have continued. Here is what I think will happen (I hope will happen). The leaf drop will continue for a little while longer, then stop. New root growth will develop due to the high aeration, excellent drainage and natural pH afforded by the CHC/peat moss medium. A new general flush will restore the tree's folage after the roots have generated some new growth tips. I would not fertilize for a while, then keep any fertilizer application below 200 PPM, 150-PPM might be better. Good luck to your tree. Drop me an e-mail using "My Page" I would like to know of the tree's progress. Regards - Millet

G-man, when you used the Microblast, did you also apply the Earthjuice Nitrogen? Considering Earthjuics is an organic fertilizer, using both shouldn't be a problem. In fact, I've read posts where ppl use several EJ's on a single plant, for different reasons.
I'd have to disagree about Superthrive..one will only know if with experimentation..Toni

gman, though it looks from the photos as if the Meyer rootball might not have occupied the entire volume of the pot, it does seem like there wasn't a lot of extra space. Assuming that you put the tree back in the same pot, how did you distribute the rootball in the new medium? Seems as if it would be difficult to spread out the roots and get an even distribution in the CHC mix without tearing the roots. Or does that not matter a lot?

Also, do you worry about the tree getting rootbound?