You probably wont have trouble with a coral banded and a cleaner or fire shrimp in a 29. I know that every tank is different, and each individual animal can be different, I used to have a pr of coral banded with cleaners in a 12 nano, and now in my 24 gal nano I have a pr of atlantic cleaners, pr of harlequins and a pr of Stenopus pyrsonatus (a larger more agressive relative of the common coral banded). While they are an agressive shrimp, it is mostly toward other Stenopus, and small shrimp they can easily over power and eat. The coral banded would go after the sexy shrimp.