If your lighting's halfway decent you could do Java ferns and water sprite. Water Sprite is a nitrate sponge and I usually have some growing in most of my tanks either planted or floating. I have it in my GT tank along with fake plants from the reptile dept at Petsmart they suction cup to the glass and are great cover, hide equiptment and don't take up any room in the swimming area pluse add alot of area for nitrifying bacteria to grow on.