Will golden and splended mantellas use vertical space?

Sorry you didn't get a response to this sooner. Most mantella species will climb, but they are mainly terrestrial. I personally would go for something more horizontal than a hexagon terrarium, but you could always use the vertical space to grow more (and more elaborate) plants.

Thanks so much for replying! I had a feeling they were more terrestrial but ive seen my golden mantella climb all the way to the top of his 10 gallon so that got me kinda curious. I think i am goin to proceed with the 30hex, either way there will be more room then in a 10 gal. And considering ive found some prehistoric looking "air ferns" the vertical space would be best. Thanks so much!

Depending on type of mantella they do climb, the aurantiaca and pulchra can be kept quit simmilair in conditions.
When kept to warm they will die from 'heat-related-muscle-spasm-syndrome', altough it's mainly the aurantiaca you have to be carefull about.

Mixing both species might seem to be a good idea because of this, but you better keep them seperated.
The Pulchra are quit nervous and the aurantiaca is rather bold, this may cause the pulchra to stress out.
Not to mention the different skin secretions and possibility of cross breeding.

I would use the high tank for the aurantiaca since they are more secure and will use the open climbing space.
For the pulchra you do best by providing floor space with lots of hiding spots.
In both tanks a large amount of leaf litter is something that can't be missing from the tank.

Thats good info! Since i want to breed mantellas i am making sure they are in a species only set up. I dont want to end up with some lil hybrid monsters lol though the coloration combo would be interesting. So yea using a vertical setup would be good for my golden mantellas. Plus a vertical set up would be easier to keep cool. I think i am goin to have to move my mantella set ups into a cooler room for now though, we had to turn on the heater this week for winter and i noticed higher temp range in their tanks.