Hi Paul ,:welcome:
If it is a common, it will love fresh raw veggies. Zucchini , red and green bell peppers,skin down ,a list on PP here to give you more ideas and wood is always nice for them to rasp on(I boil mine so the tannins don't leech into the water and give it a ''tea'' color--and wood can be purchased at the aquarium store ) oh, the veggies will float so you will need to purchase clips to sink it or there are other things made to sink veggies. good luck !