It can be any size really, with whatever fits in your viv, mine are about 20cm square, but its the depth thats important, really no more than 25mm deep, otherwise the adults- if they are adults- can drown, especially if the male is trying to mate with a female again!!!,
put a piece of wood or similar in so it acts like a ramp so they can get out.
My axie is acting woerd he was a rescue as stated in a different post he got better and now seems to be deteriorating again...again all tank conditions are OK and as should be. He seems to have some black dapple like pattern under his bottom lip? Is that normal? And his two back feet have a little wierd growth? Almost? Tiny tiny tiny lump. His capillaries in his feathers also appear darker and more visible. Any help would be appreciated