anubias are slow growers so don't expect too much...you could attach the plant to a piece of wood

the only thing bad about sand when it comes to plants is the sand can get rather compacted whereas the gravel or pebbles (river pebble is a good way to go) provides enough spacing between all the pebble/gravel so the roots can flourish through the cracks

you shouldn't add any chemical, just let the fish poop fertilize the plant roots

I am sure Alasse and others can suggest more ways to help with the plants

Does well in sand nat....i currently have it planted in sand, growing well and throwing off runners big time!

Low tech plants that dont require much care

Java fern (the 3 kinds)
Anubias (very slow growers)
Crypts
Java moss
Val