If you are in Florida, I suggest you use a very well-draining mix if you plan on re-potting or up-potting this plant.
While most people will recommend manure and organics, you may be better served in the long run with a sandy mix that drains well. You get enough rain to keep the pot moist in the summer and mango does surprisingly well with a little less water than it does with a little more water than it needs.
If you wish to use manure, use it as top dressing dont mix it into your soil.
I think this is because in Florida, compost breaks down very quickly and results in compaction in your pot, reducing the soil's ability to drain well, which is bad for your roots. I have pulled enough struggling plants to find nothing but brown roots in a very wet medium, despite not having applied any water. If you are in Florida, do not mix compost in large quantities in your potting soil. Use sands, perlite, some say pine bark fines (though I have never used this) should make the bulk of your material, and your objective is good drainage.
A quick search for mango mix on the forum should point you to some tested mixes that make strong plants.
