Help, I think I damaged toadstool mushroom

[Debramb]

Ok, Bayer advanced, noticed 1 dead red bug, rinsed and rinsed, added 1 drop CoralRX pro to 8 Oz water, rinsed and rinsed, put in tank and noticed necrosis on edges, scraped off and pulled out with a net, 6 days later, still dead edged. Did I kill my animal?

 

[vetteguy53081]

They are tough and heal real well. Just assure water conditions are favorable