In my opinion, a 12x12x18 tank is too small for any dart frog adults of any species. It is not just due to the small space (which is definitely a big part of it) but also due to the difficulty of maintaining proper wet/dry periods in the tanks for the frogs to choose.

Most people on this board recommend 18x18x24 as a minimum for the smaller species and 24x18x24 for the medium to large species. The bigger the better for your enjoyment and the frogs well being 🙂

 

My Epipedobates anthonyi are huge jumpers and when I get the space I plan on upgrading to a 36x18 footprint. I think 12”+ a background is just way too little space for them.

 

Yeah, I kept imitators in a 12x12x18. I did not like it at all. I felt it was too small for the pair of frogs. Also, due to it's small foot print it always felt like the frogs were likely to jump out whenever I did maintenance.