Hello guys! My betta, Conan, who I've had for about 8 months has recently fallen ill and I'm not sure what it is. He lives in a cycled and filtered 3.5 gallon tank with a heater normally kept at around 80-81 degrees. I do a 30% water change every two weeks and I rinse off his decorations at the same time. Recently when my friend visited she accidentally unplugged his heater and I didn't notice for a couple days. He was in temps way too low (73-74 degrees) for that time. I only noticed something was wrong when I saw the large fuzzy gray growth on his dorsal fin. He also seemed to be possibly missing a few scales and one of his eyes was cloudy. Since I've noticed I've done a 30% water change and added about a teaspoon of aquarium salt to his tank as well as given him a 10 minute salt bath. The fuzzy parts of his fin have mostly disintegrated leaving a red hemorrhage spot but his scales still seem to be missing and both eyes are mildly cloudy now and I'm thinking he probably has popeye. The missing scales appear white in the picture but in reality they're mostly darkish skin color. I don't know what the other disease is! It's not fin rot, he had a bad case when I first got him and it looks different than this. Could it possibly be columnaris? Or something else? I'd appreciate any comments, help, or medicinal suggestions!! I've included some pics that were the best I could get. Thanks in advance!! I want my boy to be happy and healthy again!