also be careful nmot to add to manythings at once. sure it is great to have all kinds of new stuff "appear" but slow it down. Sponges are really hard to keep alive in a new setup, also when te die they may, kill off stuff in your tank. my LFS have a sponge dieoff and it killed a large percentage of the stock that they had in the tank with the sponge. (I do have sponges bTW) so i think they are cool, but wait until you have a mature aquarium