Thanks Adam, I didnt measured the pH level yet, I am a dumb newbie in this subject, but the paulista jaboticaba never had a single problem and it was planted on the garden soil some time ago... so I believe that the soil is not too bad (it has lots of worms...). (not red soil neither, red soils are from Misiones, far from here)
Maybe I was wrong about adding too much compost to the poted trees, as I read that compost makes the soil more alcaline... so I bought some pinocha and sphagnum and I will be adding it when I repot... for now I am using that as mulch for poted jabos (dont know if it really works as mulch)
and watering with just rain water and chelated iron all the ones that got bad (cabelluda, some others that seem to be sabara, coronata, grimal and vexator)
They seem to recover slowly, but I dont want to fail again in the soil subject.
Also, I bought an italian fertilizer that is low on nirogen and it is organic, something like 4-15-3, and fertilized ALL my trees with that... hope it works :S