Pods are always desirable, don't go buy anything that only eats them. Sixlines can disrupt a large tank, in a 29 I wouldn't try one. Doug's right you wouldn't think it is so but it is true for most wrasses a 29 is like a prison cell, and the fish would likely starve. Mandarin's are iffy in perfect conditions, if you're ready to buy live pods to feed the price is coming way down finally. I'd let those pods have babies and the babies have babies before I'd add a predator to the mix. At night you should see them flying all over the tank, you want that, they are natural reef inhabitants and you should be glad to see them, be patient.