I have a Fluval Spec V that was home to a lovely male betta until he developed what my ifs guy believed was a fungal disease that ate away at his flesh. He died about three months ago, but I have kept the tank running as it is home to several plants and a pair of nerite snails. I'm now wondering how I might use the tank for a fish again, but I am leery since I don't know exactly what killed my betta and worry that there might be something contagious lurking in there. I also don't want to chuck out the plants and snails that are still thriving in there. What advice do you have for making the tank safe for another fish? TIA.