question about n. bervis and puffer fish

[TigerBarbMama]

i have been doing alot of research on cichlids, and i have decided to put the lake tanganaki (the shell dweller ones) in my new 20 gallon. according to cichlidrecipe.com i will be able to fit 6 cichlids in the tank rather comfortably. now i kno that puffer fish are agressive and the puffer fish will be around the same size as my cichlids. i was curious that once my tank is done cycling if i should put them together. or will it be too much.

or ill take suggestions of what type of fish will go with my cichlids.

[ChilDawg]

As a rule, puffers deserve their own species tank, due to the fin-nipping nature of many specimens. Also, territoriality of cichlids would exacerbate the situation until, eventually, a cichlid dies from fin rot or the puffer dies from injury (and tetraodotoxin kills the remaining fish).