Also, that is certainly a small container.  Soon you need to put the tree into a larger container.  When you do, move the tree in a container about 3 inches wider. The best to you and your tree.

Straight of slanted  doesn't matter.  Just measure a couple feet above the soil line and make your cut.

brian, your not the only one, my greenhouse has flooded twice in the last 20 years.  As it is said..."This too shall pass".  Actually I bet some of your trees loved it.

Pictures 1 & 2are showing the classic symptoms of an iron deficiency. Iron deficiency symptoms in citrus are:  New leaves with green veins on otherwise yellow leaf, and no wide green area sticking out from the vein.  Deficiency often caused by high pH rather than a shortage of minerals.

Pictures 3 & 4 :  Looking at the pictures it is difficult to see if the leaf veins are either yellow/orange or green.  Yellow veins would show an iron deficiency, while green veins would demonstrate a nitrogen deficiency.  Since both trees are yours, and are showing  deficiencies at the same time, they are both most probably suffering from the same problem.  You wrote that you are fertilizing with Foliage Pro but have not stated the amount of fertilizer used and how often you fertilize.  Foliage Pro does have a 0.1% iron concentration,  but with the rapid drainage of a 5-1-1 medium you could be washing out much of your fertilizer.  Know that citrus require MORE nutrition than most other plants.The quickest iron deficiency remedy would be a foliar spray with an Iron Chelate solution. Beyond the quick help of Iron Chelate foliar treatment you need to correct the pattern of care that caused this situation in the first place.  I would not be surprised that you are under fertilizing. The best to you and your trees.
 

Valentine seed does not produce true

https://oregonstate.edu/dept/nursery-weeds/presentations/Workshop1_06.pdf

The pH of coir, depending on the manufacture is normally 5.5 to 6.8 which is very close to the exact pH for citrus growth.  Using a pH meter in such a lose medium as 5-1-1 would be difficult.  The first thing that comes to mind is the use of the pH paper strips that can be found in many larger garden centers.   Stick the strip down into the 5-1-1 and leave for a few minutes, then check the color change.    You could also take the pH of the affluent water. by setting a small container filled with your 5-1-1 into a larger clean container and fill the larger container up to the rim of the container holding the 5-1-1 with distilled water.  Let it soak for an hour and then take the pH of the water.  Just an idea.  Actually using coir with its pH range of 5.5 to 6.8, you will be very close to the recommended 6.5 pH.

I've used coir, and find it a good material for citrus.   The pH of coir is, depending of it source, 5.5 to 6.8 which is correct for citrus.  Depending on the source of peat, the pH of peat is 3.6 to 4.5.  An extra good point in favor of coir (at least for me) is that when dry coir is a lot easer to rewet than peat moss.  Growing in mediums such a 5-1-1 or 5-2-1 where the drain through (water pass through) is rapid, coir  retains more of the water than peat, but still allows for the higher oxygen level for the roots to respire. Chemically, coir which comes from the coconut contains potassium,  manganese, copper, zinc and iron.  I like coir.

From looking at your soil in the picture, it looks like you have a tractor and a disk.

Johnny, the amount of leaves on your Yosemite Gold tree are so very full I can't see a single branch.  The growth is very columnar in shape.   

Ilya11, the FD you show above as being the tree that is comming out of dormancy earlier then your other FDs, then I would assume that it will also be less cold hardy than your other FD trees.

Poncirusguy, a New Zealand Lemonade tree grafted on a Sour Orange rootstock is very interesting. I like that combination.  I bet that combination will produce a lot of high quality fruit per size of the tree