Blood parrots get pretty good sized I would not recommend even one. I would say that in my opinion you need at least a 55gal for one. If you want three I would say a 90gal . . . but that is just my opinion. I have seen some blood parrots around 6 to 8 inches and due to the odd shape of their body they dont swim very well, kinda waddle through the water like a fancy goldfish. Being carnivorous they can be pretty messy too.
You could get the blood dwarf parrots. They only reach 2" maybe 3" in size and you could have your group of 3 in your 29. I would agree that you would need a larger tank for the fullsize parrots though. I did have 2 in my 55g with some other fish and they were a happy pair.