Ryan,
I have Preto for exchange but am not allowed to export neither you may import.
but I may export 'talking' !
Looking at the small Preto on your picture, and for rapid results, I believe that a treatment from now on with the correct dose of Amino Acids could well change the picture for the better. This is what I do in similar situations and always wit very good results The liquid formula I use contains:
Amino Acid totals -------14,4%
Amino Acid free ---------12%
Nitrogen total ------------08%
Mostly prepared from plants, is a rather dense product (1.3) , thick and looks like asphalt
This should be available in you area with the local brand name.
My dose for above formula is 2 table spoons per 12 litre of water
I do use the fish products suggested by Paully, fishmeal as well and they are great for the coming upotting of that Preto and others and, please grind and use all those crab shells, another good supplement of calcium and micros.
OT - by the way once you talk bait, my best an most productive option for the hook are the med size
'shell less' crab. This works as candy for the heavier stuff
Francisco
Portugal