OK here's the reply-
Thanks for your e-mail. The fish tank is completely removeable and easily slides in and out of the bag. The entire top of the tank pops off for easy access and easy cleaning, water changes and feeding. The tank is quite sizeable. Approximately 4 times the size of those that Betta's are kept in in the fish stores. As with any fish, if he were to become ill, I would consult your local pet store (they sell different water drop type medicines for fish) I have never had a problem with any of my Betta's to date as they seem quite resilient. Also, I've never lost one either : ) The fish breathes in and out of the water. There is quite a bit of room in the tank for air and each time you open the container (we recommend daily for feedings) the tank re-oxygenates itself. My personal fish " Bubba" has been traveling with me for well over a year and is excellent shape so the bag is definitely tried and true, Thanks so much.
4 times the size? Well, betta's are kept in cups of water. TEMPORARILY.