Rock dust, fish emulsion, seaweed extract, grass clippings (if the grass is healthy), humic acids are good sources of micronutrients. Most minerals are found in trace amounts in soil.
The micronutrients that citrus needs are zinc, manganese, iron. These are the ones that usually show up as deficiencies on citrus.
Citrus also likes to be slightly acidic and are heavy feeders.
I do keep my citrus in pots, but I use vermicast and citrus food containing micros(not organic). I will occasionally use fish emulsion, but my neighbor complains about the smell so, I don't use it often. I have not used seaweed extract, but people have said it is very good. Blood meal should be a good source of iron.
Happy gardening in Hawaii. Gardens are where people grow.