BNs will compete (eat) the algae. Depends on weather you want all the algae for the Troph.
petricola/lucippinis may get the slow and stupid of the young but have not impacted much on the Troph when I try it.
Again it depends on what you want.
For max Troph in the tank and no messing, max breeding, keep it Troph only.
Interest add the Synos. I have em. Very happy with them. BNs in other Tang tanks but took em out of the Troph tanks. I just prefer cleaning the algae off the glass (they do not get it all anyway) to these ugly guys in there I guess.
Any other fish in the tank reduces the number of Troph you can keep in there.
I love my Synos in there but its not the most productive or easiest way of keeping/breeding Troph just more interesting . :thumb:
Maybe its best left to those a bit ho hum with keeping and breeding in species tanks?