I looked at your photos. If there is a nutrient or salt problem,
it is minor. Your plants look quite healthy with only slight
chlorosis.

However, the container looks quite small. My dwarf citrus are in
18 inch (45 cm) redwood tubs, cylindrical and as deep as they are
across. I will soon replace one tub that is rotting with a
terra-cotta pot 20 inches (51 cm) across -- tapering to slightly
less at the bottom -- and 17 inches (43 cm) deep. It is very
similar to the pot in your IMG_3231.jpg.

You need a large container so that you can keep the soil moist
without it getting soggy. Too much water in the soil is as bad as
the wrong pH or too many minerals. Indeed, excess water causes
chlorosis.

With a large container and an acidic, well draining potting mix
(with acidity maintained with acidic fertilizers), any excess
calcium in the water or nutrients will readily leach away. This
cannot work, however, in a small container because the soil gets
too soggy before proper leaching occurs.

--

David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening pages at http://www.rossde.com/garden/