I have a 29 gallon tank with 6 gold ocellatus, 2 white calvus, 2 a. comps and a bristle nose in it. The ocelllatus are about 1 to 1.25 inches. The calvus and the a.comps are about 1.5 inches. I am thinking about adding 3 petricolas to the tank my lfs just got some in that are about 1 inch. do you think that is a good idea to add the the petricolas or do you think they will give the occies a hard time or the other way around? and what is the difference between the a. comps and the calvus?