Building an aquarium is not the hardest thing to do on stardoll, it is really expensive. I dropped 150 starcoins. Yeah, yikes. Anyway, I did it by going into the Animal section, and then to Aquatic. I bought three animals:goldfish, starfish, and seahorse. Go with the animated ones. It'll look more realistic. Second, buy 3 pieces of "oceans." Go into DIY. They are 30 starcoins each. Yikes. Lastly, go into Furniture, then Table, Then Coffeetable, and then brown. The table I used is from Roots. In the end, you get a realistic looking aquarium. The photo above is from my friend, Jordan's Suite, but check out mine for a better one!