First off....Welcome to the site.

I would suggest getting a digital thermometer/hygrometer instead of one of those 'gauge type' deals from a pet store. Your temperature is going to be the most important thing to get correct right now. Get you warm side to 92-94, cool side to 82-84, and humidty around 50-60%. If you are not keeping you ball pythons in the correct conditions, that is most likely the reason for the 'fasting' and can result in a unwanted trip to the vet to treat respiratory infections. The aquarium size sounds just fine but I would not recommend keeping two ball pythons in one enclosure. Keeping them in the same enclosure can cause stress on the animals due to competion for space. Also, if one becomes ill you will not be able to know whos feces is whos, etc. And worst case...one may eat the other. Ball pythons really do not need branches because they are a 'ground dwelling' species....they naturally live in field and holes in the ground. The reason the ball pythons are burrowing under the water bowl is to use it as a hide. Check your current hides for size. Half-logs are also not one of the best hides, because ball pythons tend to like hides that they can touch all sides when they are in the hide (ie. under the water bowl). If you have any plastic type tubs (i.e. butter tubs, coolwhip tubs) cut a hole in it and place it in the enclosure as a hide...they may like that better. Hope that covered it all....if not I am sure someone has my back. If you need more detail just ask