So I am soon to be a first time creasted owner and I have a question about tank size. I really like the exo terra 18x18x24 and have heard its great for adult cresties but is a tad overpriced in my opinion. So does the 12x12x18 give them enough room when they are adults? I've heard it can make their tails go wonky if they find have enough room. Any comments help, thanks!