I would try java fern. It is very easy to maintain. Java fern likes low light and will grow fairly quickly bUT wont take over your tank. Also, I dot know if this is fact, but it has a bitter or undesired taste to fish. I. Any tank I've had it in, the fish have left it alone. With all the cool decor in your tank it would be perfect. Tie the rizome (root) with a fine thread to the fixture of your choice and that's it. Don't bury the root. Once the fern starts to thrive it will attach itself to the objext its tied to. It will spawn at the tips of the leaves and you can cut them off and start the process over again. Its avalable at most pet stores that have plants. I hope that was helpful! I love the stuff, But sadly it's the only plant I know anything about, I wish I knew more.