2OceanLovers : AFAIK PLTA's don't split...they just keep growing and growing. You're going to either have to upgrade to a bigger tank or think about rehoming her at some point, as a 29 is not a suitable long term home for her.
I have an H Crispa right now that is about 14" across at full extension and will continue to grow. She dominates my 120.
flowerkid: You're on the lower end of the lighting requirements for nems, but it's not impossible. It'll just be more difficult, and your nem will require the best of the best in water pristinity. Also, if your nem becomes stressed, the lower level of lighting might make it harder for it to recuperate. There aren't too many nems that I would recommend to go into a 29, you could probably get away with putting a Bubble Tip in there. Just make sure that whatever nem you get is far larger than your clowns, as many of the more aggressive clowns can love a small nem to death.