Salvinia natans is a floating plant, slow to start off as it gets use to your water but grows wild when it gets going. I scoop out half of it every two weeks from my 125L Looks better than duck weed imo.
You could then get an anbubias or Java fern as a feature plant, both very hardy, no need to worry about substrate you tie them to rocks or driftwood and they grow slow so you're not pruning them all the time like val.
Floating plants soak up the nitrate easy to remove (just don't throw it in a river, pond or down the drain) and you have a nice feature plant in there as well.
Last edited by EnderUK; 12-21-2013 at 05:20 AM..