We have sharks!!!

and a 30 gallon tank!

We went to buy a shark, not realizing that they require a very large aquarium. Luckily, I already had a 30 gallon tank. We have four sharks, two of which can get as large as 13 inches and the other two can be 8 inches. It's hard to see them in the pictures because they are so small...what are the chances they will all live to get that big?!