Help - Rapid Finrot?

[Hanako]

The Jungle Fungus Clear says that a 25% water change could be done after 4 days, and then re-dose the full amount. Should I follow this? Or do a 100% water change and redose, since he's in a bowl?

 

[ral]

I would do 100%. If he is in a bowl, his water should be changed at least 100% every 3-4 days (assuming a 1 gallon bowl).