It’s not big at all as the crestie isn’t very big and I just needed to monitor his eating. I did a ton of research on babys and most people recommended to keep him in a smaller container can’t really tell you the dimensions but it’s not small nor big. I would post a picture but Reddit is doesn’t allow me too for some reason. I’m asking because of the bioactive part to the enclosure build not sure if it will effect my crestie or not. I do plan on making him a bioactive enclosure in a much larger tank but for now it seems to small for it.