I am cycling my 20 gal nano tank and trying to decide on a QT/hospital tank. I am wondering if a Fluval Evo V (5 gallon) is going to be too small and if I should just go ahead and get the Fluval Evo XII (13.5 gal)? There isn't much price difference between the two but space is at a premium in my apartment, so the smaller the better, but I don't want to make it too cramped. With only a 20 gallon DT, I am obviously not going to be adding anything huge. What are people's thoughts?