Cichlid Cover

HI! This is my first posting to this group, so please forgive me if I do
not use appropriate "etiquette" ..actually, a gentle reminder of what
is/is not appropriate would be appreciated.
I have a 18 tall with 3 dwarf Mbuna Cichlids .. Socolofi, Red Zebra, and
Demasoni ... I have an amazon sword and a few arachanis ... and the
three little piggies (and are they ever piggies!!) have pretty much
"staked" out their regions of the tank. the demasoni of course has
claimed all of the really cool hiding places in a large rock piece ...
the Zebra and the Socolofi hang near the middle/top .... what I would
like to do is offer them some more cover from the demasoni when he gets
a "wild worm up his butt" to chase them all over ..... what plants could
you reccomend? something that will float and possibly "dangle" down a
bit???

Thanks a "bunch" ..... Dawn