The new ones look fantastic....Are you feeding them enough Nitrogen? Did you lime that 5.1.1 mix? What fertilizer are you using?

Esmeralda, 1 tbsp of vinegar may be too much. Did you check the pH of your water? I would add 1 tbsp of FP and 1/2-1 tsp of vinegar. The lower leaves of that tree look deficient, but the new ones look good.

The leaves on your tree are showing a magnesium deficiency. My guess is that you have not fed your tree with magnesium (Epsom salts MgSO4) in some time. The symptoms of magnesium deficiency always shows up on the tree's older leaves, because in citrus magnesium is a translocation element. Translocation means that when a citrus tree is deficient in magnesium the older, more mature leaves, translocates their stored magnesium to the tree's younger leaves to insure that they are given all the nutrients that they require (the tree's priority). Thus called a translocation element. Magnesium deficiencies can occur at any time of the year, but are most common in the fall . To cure this deficiency dissolve one tablespoon of Epsom Salts (Magnesium Sulfate MgSO4) in one gallon WARM water (Epsom salts poorly dissolves in cool water) then apply to the root zone, it can also be applied as a foliar spray. It could take several applications a couple weeks apart, until symptoms disappear. Epsom salts should be applied to container tree's three times a year, especially for trees in fruit. - Silica

Silica, this is interesting. So even if my trees do not look deficient (I do have a Persian lime that has a few older leaves like that, but I figured that was not fixable), I should apply Epsom salts? I had no idea, but will do it if it will cure this issue on my tree. I can post a pic tomorrow. Thanks for your help!

great to have people with so much knowledge on this forum, although I don't know what half means sometimes I am picking up quite a few things, thanks to all of you

Thank you Silica...we all learn quite a bit from your knowledge. I found that two of my older trees and one not quite as old are showing older leaves like that. I will give them Epsom salts perhaps tonight.