All right so i have had my Biocube 29 setup for about 8 months and I was thinking of setting up a new 10 gallon for a mantis shrimp. What do you guys think of that? Thanks

go for it, its very easy to get N. wennerae and to set up a gorgeous florida biotope, wennerae are also quite active ime, though it may ignore you.

Have I lost it, or is it a terrible idea to put a mantis shrimp in a thin glass tank? And won't it outgrow a 29g?

Mantis shrimp are cool, but have certain needs to keep one alive and your floors dry....

Get a small species in a 10g..

N. wennerae is a small species and would to well in a 10g. the only mantis you really need to worry about breaking glass are ones over 5" and thats incredibly rare, they just don't do it and one that size has no business in a 10g tank. once you get into glass 3/16" and thicker you don't really need to worry about it getting broken.

that is actually a myth there has only been one reported incident where a mantis has broken a tank and been proven to be the culprit and that was by a large peacock mantis that was being kept by that mantis expert(i forget their name right now) who was showing a camera crew around the facility and one of the camera men put the camera right infront of the tank and the peacock attacked it and busted the glass. that is the only incident that i have discovered where a mantis has broken a tank. now there are only 2 species that even have the capability to break tanks and they are large peacocks and chigira(sp?) who are both species that burrow through rocks to make their caves.