I would have to agree with Jason that you should filter that water if keeping it like that or go with a huge deep dish you can change daily. There was a guy on here a few months back that had his ABF die in the water on him. He took excellent care of this guy and couldn't figure out what happened, after doing a test on the water he found the ammonia and nitrates were threw the roof and that's what killed his frog. He even had a filter and was doing his 25% water changes every few days. These guys can take some huge pees so you may want to be carefull with the water and if you keep this way you may want to have a water quality testing kit handy so you can check the levels every few days. As I mentioned he had his guy for around probably same amount of time as you have had yours and he was devastated that's what killed his perfectly healthy frog, I wouldn't want you to have to go through it too.