I have trifoliata and yuzu with the same soil mixture, sand and humus substrate of worms. The tips of the leaves start to dry out, the same thing happened to the yuzu that suffered from root rot, but I thought it was due to that problem.
In addition, you can see that the new leaves of the trifoliata are light green, almost yellow. I don't think it's Fe chlorosis.
I have added a potting pill with potassium, phosphorus and nitrogen, but I have not noticed any improvement.
New leaves are always light yellowish green. Citrus leaves darken up as they mature. I do not see any nutrient deficiency. Do you flush your container's medium every couple months to wash out any soluble salts buildup? All in all your tree looks quite healthy.
Great, thanks for the answer, it's my first time germinating citrus and the first leaves were green, even in the yuzu none have come out yellow, so I thought there would be some problem with the trifoliata.
I have never changed the soil yet because they are very small, the water is acidic and I don't want to use much inorganic fertilizer for now, the pills I put in it were because I thought there were problems.