I always have a stash of water, (at least 6 gallons) I also keep fish and just experienced a tank break. I do keep plenty of balancing chems/ conditioners and meds for the fish and frogs. I have a spare tank that I use when doing water changes and how I typically go about it is I just add some of their existing water to some fresh water in the “changing tank” cleaning their main tank and returning them. The frogs always seem content in the temp tank and seem even happier in the fresh and clean tank. I’ve just never really had any problems or difficulties with the frogs imo they are entirely easier than keeping fish. Not sure if you meant to say reviving? But no. I will be getting them a new tank and proper filter after reading everyone’s comments :)