Think she should add some boiling water to the substrate (when the tort isn't there to kill it off)?Shell fungus. Probably something to do with the substrate. Is it moist at all?
Treatment is pretty simple and straightforward. Get a toothbrush, a bottle of Povidone or Betadine iodine, and some athletes foot cream (anything with clotrimazole) at the pharmacy. You can use chlorhexadine as well, but I believe it has to be order from some online vet clinics or whatever.....More expensive as well.
Anyways, dilute iodine 1 parts to 10 parts water. Scrub the plastron with the toothbrush and the iodine dilution. Do this daily for about the first two or three days. Afterwards, dry off the shell and put the clotrimazole cream on. It's best to do this at night, and place them in a clean container back in their habitat, so they don't get everything stuck to their shell, or get the cream in their water or something. Repeat the cream daily for a week to 10 days and see what it looks like by then. Usually goes away very quickly.
Think she should add some boiling water to the substrate (when the tort isn't there to kill it off)?
It doesn't kill fungal spores:It's an interesting idea, but I doubt it would work. I honestly don't know. Not really familiar with what kind of fungus in specific causes this. I know substrate can play a big factor, but which substrates leaves a lot to question. I know that an acidic environment prevents shell fungus (using spaghnum moss works great for this reason, with young red foots). People will say that an overly moist habitat causes it, but I've seen it happen relatively dry as well so....Not really sure. You could just replace all the substrate, but I don't really think you will need to.