Start out small on the clean up crew if its a new tank with not much algae. They can starve if there is not enough food. 20 turbos thats alot IMO
.. Feather dusters IMO
should be kept in mature tanks the feed off the phytoplankton and really have little to do with cleaning it.
Get a varity of snails a few turbos, astraea,ceriths, nassarius. I have a mix of scarlet and blue leg hermits, just toss in some empty shells to help with the fighting.
Conch snails can get big real big.......