BL1
.............
Clowns just don't use a lot of the tank, it's how they are. You can get him another clown but they won't use anymore of the tank, maybe a bit more since its two. Clowns don't need anemones and your tank is too young for one currently. They're very hard to take care of and the clowns won't necessarily go for them, there are a bunch of coral options that you can try though that would be much easier to take care of.